Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Bleach 3.3.0 includes a fix for CVE-2021-23980: A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.

Affected versions of the Bleach package are vulnerable to Cross-site Scripting (XSS) due to improper handling of whitelisted tags in the bleach.clean function. The vulnerability exists because the bleach.clean function allows certain raw tags, such as "noscript" and "script", to be whitelisted, which can lead to unintended HTML mutations. An attacker can exploit this by crafting malicious HTML content that includes these tags, potentially executing arbitrary scripts in the context of the user's browser session.

Bleach 3.1.2 includes a fix for CVE-2020-6816: Mutation XSS via whitelisted math or svg and RCDATA tag with strip=False.
https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743

Bleach 3.1.4 includes a fix for CVE-2020-6817: bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).

Ipython versions 8.0.1, 7.31.1, 7.16.3 and 5.11 include a fix for CVE-2022-21699: Affected versions are subject to an arbitrary code execution vulnerability achieved by not properly managing cross user temporary files. This vulnerability allows one user to run code as another on the same machine.
https://github.com/ipython/ipython/security/advisories/GHSA-pq7m-3gw7-gq5x

IPython 8.10.0 includes a fix for CVE-2023-24816: Versions prior to 8.10.0 are subject to a command injection vulnerability with very specific prerequisites. This vulnerability requires that the function 'IPython.utils.terminal.set_term_title' be called on Windows in a Python environment where ctypes is not available. The dependency on 'ctypes' in 'IPython.utils._process_win32' prevents the vulnerable code from ever being reached in the ipython binary. However, as a library that could be used by another tool 'set_term_title' could be called and hence introduce a vulnerability. If an attacker get untrusted input to an instance of this function they would be able to inject shell commands as current process and limited to the scope of the current process. As a workaround, users should ensure that any calls to the 'IPython.utils.terminal.set_term_title' function are done with trusted or filtered input.
https://github.com/ipython/ipython/security/advisories/GHSA-29gw-9793-fvw7

Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.

An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker who controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the '_punctuation_re regex' operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, `/`, `>`, or `=`, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the `xmlattr` filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting _values_ as user input continues to be safe.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous.

When Tornado receives a request with two Transfer-Encoding: chunked headers, it ignores them both. This enables request smuggling when Tornado is deployed behind a proxy server that emits such requests. Pound does this.

Summary: Tornado's interpretation of symbols `-`, `+`, and `_` within chunk lengths and 'Content-Length' values contradicts the HTTP RFCs stipulations, potentially creating an avenue for request smuggling. This issue is generally found when Tornado operates behind specific proxies that understand these non-standard characters diversely, mostly observed in earlier versions of 'haproxy'; however, the latest version remains unaffected.

Details: Tornado utilizes the 'int' constructor to decipher the 'Content-Length' headers and chunk lengths in the locations mentioned below:

`tornado/http1connection.py:445`
Python3 code: self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`
Python3 code: content_length = int(headers["Content-Length"])

`tornado/http1connection.py:671`
Python3 code: chunk_len = int(chunk_len_str.strip(), 16)

Notably, though the equation `int("0_0")` equates to `int("+0")`, `int("-0")`, and `int("0")`, using the 'int' constructor as a strategy for validating and parsing strings containing ASCII digits only is proven inadequate.

Tornado web framework affected versions contain a performance vulnerability in their HTTP cookie parser. When processing specially crafted malicious cookie headers, the parser's algorithm can exhibit quadratic time complexity. Since this parsing happens in the main event loop thread, it can cause the server to become unresponsive and block the processing of other incoming requests due to excessive CPU usage.

Tornado 6.3.2 includes a fix for CVE-2023-28370: Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

Tornado’s curl_httpclient.CurlAsyncHTTPClient class is vulnerable to CRLF (carriage return/line feed) injection in the request headers.

Pygments 2.15.0 includes a fix for CVE-2022-40896: The regular expressions used when parsing Smithy, SQL/SQL+Jinja, and Java properties files were discovered to be vulnerable. As a result, pygmentizing a maliciously-crafted file of these kinds would have resulted in high resources consumption or crashing of the application.
https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages-part-2

Pygments 2.7.4 includes a fix for CVE-2021-20270: An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Pygments 2.7.4 includes a fix for CVE-2021-27291: In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.

Gunicorn 20.0.1 fixes chunked encoding support to prevent http request smuggling attacks.
https://github.com/benoitc/gunicorn/issues/2176
https://github.com/p4k03n4t0r/http-request-smuggling#request-smuggling-using-mitmproxy-and-gunicorn

Affected versions of the gunicorn package are vulnerable to HTTP Request/Response Smuggling due to improper validation of the Transfer-Encoding header that enables a TE.CL desynchronisation condition. Gunicorn’s HTTP parser does not consistently enforce RFC semantics when parsing conflicting or unsupported request framing—such as messages containing both Transfer-Encoding and Content-Length—so the backend may fall back to Content-Length while an intermediary treats the message as chunked.

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.

Affected versions of the nbconvert package are vulnerable to Uncontrolled Search Path Element due to resolving the inkscape executable on Windows using a search order that includes the current working directory. In nbconvert/preprocessors/svg2pdf.py, the PDF conversion flow for notebooks with SVG outputs locates and executes inkscape without a fully qualified path, allowing a local inkscape.bat to be selected and run.

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq

Ipywidgets 8.0.0 sanitizes descriptions by default.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Ipywidgets 8.0.0rc2 makes descriptions plaintext by default for security.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Jupyter Core is a package for the core common functionality of Jupyter projects. Jupyter Core prior to version 4.11.2 contains an arbitrary code execution vulnerability in 'jupyter_core' that stems from 'jupyter_core' executing untrusted files in CWD. This vulnerability allows one user to run code as another.

Prompt-toolkit 3.0.13 fixes a race condition in `ThreadedHistory` which could lead to a deadlock. 
https://github.com/prompt-toolkit/python-prompt-toolkit/commit/99092a8c6d4b411645ac4b84d504e5226e7eebb8#diff-48c0ff10dc3990285d19b3f54e6bfec763089ba1229dc6f9e88463a1046adad7R163

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Bleach 3.3.0 includes a fix for CVE-2021-23980: A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.

Affected versions of the Bleach package are vulnerable to Cross-site Scripting (XSS) due to improper handling of whitelisted tags in the bleach.clean function. The vulnerability exists because the bleach.clean function allows certain raw tags, such as "noscript" and "script", to be whitelisted, which can lead to unintended HTML mutations. An attacker can exploit this by crafting malicious HTML content that includes these tags, potentially executing arbitrary scripts in the context of the user's browser session.

Bleach 3.1.2 includes a fix for CVE-2020-6816: Mutation XSS via whitelisted math or svg and RCDATA tag with strip=False.
https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743

Bleach 3.1.4 includes a fix for CVE-2020-6817: bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).

Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.

An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker who controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the '_punctuation_re regex' operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, `/`, `>`, or `=`, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the `xmlattr` filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting _values_ as user input continues to be safe.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous.

When Tornado receives a request with two Transfer-Encoding: chunked headers, it ignores them both. This enables request smuggling when Tornado is deployed behind a proxy server that emits such requests. Pound does this.

Summary: Tornado's interpretation of symbols `-`, `+`, and `_` within chunk lengths and 'Content-Length' values contradicts the HTTP RFCs stipulations, potentially creating an avenue for request smuggling. This issue is generally found when Tornado operates behind specific proxies that understand these non-standard characters diversely, mostly observed in earlier versions of 'haproxy'; however, the latest version remains unaffected.

Details: Tornado utilizes the 'int' constructor to decipher the 'Content-Length' headers and chunk lengths in the locations mentioned below:

`tornado/http1connection.py:445`
Python3 code: self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`
Python3 code: content_length = int(headers["Content-Length"])

`tornado/http1connection.py:671`
Python3 code: chunk_len = int(chunk_len_str.strip(), 16)

Notably, though the equation `int("0_0")` equates to `int("+0")`, `int("-0")`, and `int("0")`, using the 'int' constructor as a strategy for validating and parsing strings containing ASCII digits only is proven inadequate.

Tornado web framework affected versions contain a performance vulnerability in their HTTP cookie parser. When processing specially crafted malicious cookie headers, the parser's algorithm can exhibit quadratic time complexity. Since this parsing happens in the main event loop thread, it can cause the server to become unresponsive and block the processing of other incoming requests due to excessive CPU usage.

Tornado 6.3.2 includes a fix for CVE-2023-28370: Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

Tornado’s curl_httpclient.CurlAsyncHTTPClient class is vulnerable to CRLF (carriage return/line feed) injection in the request headers.

Jupyter Notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.12, authenticated requests to the notebook server with `ContentsManager.allow_hidden = False` only prevented listing the contents of hidden directories, not accessing individual hidden files or files in hidden directories (i.e. hidden files were 'hidden' but not 'inaccessible'). This could lead to notebook configurations allowing authenticated access to files that may reasonably be expected to be disallowed. Because fully authenticated requests are required, this is of relatively low impact. But if a server's root directory contains sensitive files whose only protection from the server is being hidden (e.g. `~/.ssh` while serving $HOME), then any authenticated requests could access files if their names are guessable. Such contexts also necessarily have full access to the server and therefore execution permissions, which also generally grants access to all the same files. So this does not generally result in any privilege escalation or increase in information access, only an additional, unintended means by which the files could be accessed. Version 6.4.12 contains a patch for this issue. There are currently no known workarounds.
https://github.com/jupyter/notebook/security/advisories/GHSA-v7vq-3x77-87vg

The Jupyter notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.9, unauthorized actors can access sensitive information from server logs. Anytime a 5xx error is triggered, the auth cookie and other header values are recorded in Jupyter server logs by default. Considering these logs do not require root access, an attacker can monitor these logs, steal sensitive auth/cookie information, and gain access to the Jupyter server. Jupyter notebook version 6.4.x contains a patch for this issue. There are currently no known workarounds.

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

Notebook 6.1.5 fixes open redirect vulnerability 'GHSA-c7vm-f5p4-8fqh'. See: CVE-2020-26215.
https://github.com/advisories/GHSA-c7vm-f5p4-8fqh
https://github.com/jupyter/notebook/pull/5874

Notebook 6.0.2 updates its dependency 'JQuery' to v3.5.0 to include a security fix.

Pygments 2.15.0 includes a fix for CVE-2022-40896: The regular expressions used when parsing Smithy, SQL/SQL+Jinja, and Java properties files were discovered to be vulnerable. As a result, pygmentizing a maliciously-crafted file of these kinds would have resulted in high resources consumption or crashing of the application.
https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages-part-2

Pygments 2.7.4 includes a fix for CVE-2021-20270: An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Pygments 2.7.4 includes a fix for CVE-2021-27291: In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.

Gunicorn 20.0.1 fixes chunked encoding support to prevent http request smuggling attacks.
https://github.com/benoitc/gunicorn/issues/2176
https://github.com/p4k03n4t0r/http-request-smuggling#request-smuggling-using-mitmproxy-and-gunicorn

Affected versions of the gunicorn package are vulnerable to HTTP Request/Response Smuggling due to improper validation of the Transfer-Encoding header that enables a TE.CL desynchronisation condition. Gunicorn’s HTTP parser does not consistently enforce RFC semantics when parsing conflicting or unsupported request framing—such as messages containing both Transfer-Encoding and Content-Length—so the backend may fall back to Content-Length while an intermediary treats the message as chunked.

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.

Affected versions of the nbconvert package are vulnerable to Uncontrolled Search Path Element due to resolving the inkscape executable on Windows using a search order that includes the current working directory. In nbconvert/preprocessors/svg2pdf.py, the PDF conversion flow for notebooks with SVG outputs locates and executes inkscape without a fully qualified path, allowing a local inkscape.bat to be selected and run.

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq

Ipywidgets 8.0.0 sanitizes descriptions by default.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Ipywidgets 8.0.0rc2 makes descriptions plaintext by default for security.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Jupyter Core is a package for the core common functionality of Jupyter projects. Jupyter Core prior to version 4.11.2 contains an arbitrary code execution vulnerability in 'jupyter_core' that stems from 'jupyter_core' executing untrusted files in CWD. This vulnerability allows one user to run code as another.

Prompt-toolkit 3.0.13 fixes a race condition in `ThreadedHistory` which could lead to a deadlock. 
https://github.com/prompt-toolkit/python-prompt-toolkit/commit/99092a8c6d4b411645ac4b84d504e5226e7eebb8#diff-48c0ff10dc3990285d19b3f54e6bfec763089ba1229dc6f9e88463a1046adad7R163

Bleach 3.3.0 includes a fix for CVE-2021-23980: A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.

Affected versions of the Bleach package are vulnerable to Cross-site Scripting (XSS) due to improper handling of whitelisted tags in the bleach.clean function. The vulnerability exists because the bleach.clean function allows certain raw tags, such as "noscript" and "script", to be whitelisted, which can lead to unintended HTML mutations. An attacker can exploit this by crafting malicious HTML content that includes these tags, potentially executing arbitrary scripts in the context of the user's browser session.

Bleach 3.1.2 includes a fix for CVE-2020-6816: Mutation XSS via whitelisted math or svg and RCDATA tag with strip=False.
https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743

Bleach 3.1.4 includes a fix for CVE-2020-6817: bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).

Ipython versions 8.0.1, 7.31.1, 7.16.3 and 5.11 include a fix for CVE-2022-21699: Affected versions are subject to an arbitrary code execution vulnerability achieved by not properly managing cross user temporary files. This vulnerability allows one user to run code as another on the same machine.
https://github.com/ipython/ipython/security/advisories/GHSA-pq7m-3gw7-gq5x

IPython 8.10.0 includes a fix for CVE-2023-24816: Versions prior to 8.10.0 are subject to a command injection vulnerability with very specific prerequisites. This vulnerability requires that the function 'IPython.utils.terminal.set_term_title' be called on Windows in a Python environment where ctypes is not available. The dependency on 'ctypes' in 'IPython.utils._process_win32' prevents the vulnerable code from ever being reached in the ipython binary. However, as a library that could be used by another tool 'set_term_title' could be called and hence introduce a vulnerability. If an attacker get untrusted input to an instance of this function they would be able to inject shell commands as current process and limited to the scope of the current process. As a workaround, users should ensure that any calls to the 'IPython.utils.terminal.set_term_title' function are done with trusted or filtered input.
https://github.com/ipython/ipython/security/advisories/GHSA-29gw-9793-fvw7

Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.

An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker who controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the '_punctuation_re regex' operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, `/`, `>`, or `=`, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the `xmlattr` filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting _values_ as user input continues to be safe.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous.

When Tornado receives a request with two Transfer-Encoding: chunked headers, it ignores them both. This enables request smuggling when Tornado is deployed behind a proxy server that emits such requests. Pound does this.

Summary: Tornado's interpretation of symbols `-`, `+`, and `_` within chunk lengths and 'Content-Length' values contradicts the HTTP RFCs stipulations, potentially creating an avenue for request smuggling. This issue is generally found when Tornado operates behind specific proxies that understand these non-standard characters diversely, mostly observed in earlier versions of 'haproxy'; however, the latest version remains unaffected.

Details: Tornado utilizes the 'int' constructor to decipher the 'Content-Length' headers and chunk lengths in the locations mentioned below:

`tornado/http1connection.py:445`
Python3 code: self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`
Python3 code: content_length = int(headers["Content-Length"])

`tornado/http1connection.py:671`
Python3 code: chunk_len = int(chunk_len_str.strip(), 16)

Notably, though the equation `int("0_0")` equates to `int("+0")`, `int("-0")`, and `int("0")`, using the 'int' constructor as a strategy for validating and parsing strings containing ASCII digits only is proven inadequate.

Tornado web framework affected versions contain a performance vulnerability in their HTTP cookie parser. When processing specially crafted malicious cookie headers, the parser's algorithm can exhibit quadratic time complexity. Since this parsing happens in the main event loop thread, it can cause the server to become unresponsive and block the processing of other incoming requests due to excessive CPU usage.

Tornado 6.3.2 includes a fix for CVE-2023-28370: Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

Tornado’s curl_httpclient.CurlAsyncHTTPClient class is vulnerable to CRLF (carriage return/line feed) injection in the request headers.

Jupyter Notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.12, authenticated requests to the notebook server with `ContentsManager.allow_hidden = False` only prevented listing the contents of hidden directories, not accessing individual hidden files or files in hidden directories (i.e. hidden files were 'hidden' but not 'inaccessible'). This could lead to notebook configurations allowing authenticated access to files that may reasonably be expected to be disallowed. Because fully authenticated requests are required, this is of relatively low impact. But if a server's root directory contains sensitive files whose only protection from the server is being hidden (e.g. `~/.ssh` while serving $HOME), then any authenticated requests could access files if their names are guessable. Such contexts also necessarily have full access to the server and therefore execution permissions, which also generally grants access to all the same files. So this does not generally result in any privilege escalation or increase in information access, only an additional, unintended means by which the files could be accessed. Version 6.4.12 contains a patch for this issue. There are currently no known workarounds.
https://github.com/jupyter/notebook/security/advisories/GHSA-v7vq-3x77-87vg

The Jupyter notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.9, unauthorized actors can access sensitive information from server logs. Anytime a 5xx error is triggered, the auth cookie and other header values are recorded in Jupyter server logs by default. Considering these logs do not require root access, an attacker can monitor these logs, steal sensitive auth/cookie information, and gain access to the Jupyter server. Jupyter notebook version 6.4.x contains a patch for this issue. There are currently no known workarounds.

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

Notebook 6.1.5 fixes open redirect vulnerability 'GHSA-c7vm-f5p4-8fqh'. See: CVE-2020-26215.
https://github.com/advisories/GHSA-c7vm-f5p4-8fqh
https://github.com/jupyter/notebook/pull/5874

Notebook 6.0.2 updates its dependency 'JQuery' to v3.5.0 to include a security fix.

Pygments 2.15.0 includes a fix for CVE-2022-40896: The regular expressions used when parsing Smithy, SQL/SQL+Jinja, and Java properties files were discovered to be vulnerable. As a result, pygmentizing a maliciously-crafted file of these kinds would have resulted in high resources consumption or crashing of the application.
https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages-part-2

Pygments 2.7.4 includes a fix for CVE-2021-20270: An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Pygments 2.7.4 includes a fix for CVE-2021-27291: In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.

Gunicorn 20.0.1 fixes chunked encoding support to prevent http request smuggling attacks.
https://github.com/benoitc/gunicorn/issues/2176
https://github.com/p4k03n4t0r/http-request-smuggling#request-smuggling-using-mitmproxy-and-gunicorn

Affected versions of the gunicorn package are vulnerable to HTTP Request/Response Smuggling due to improper validation of the Transfer-Encoding header that enables a TE.CL desynchronisation condition. Gunicorn’s HTTP parser does not consistently enforce RFC semantics when parsing conflicting or unsupported request framing—such as messages containing both Transfer-Encoding and Content-Length—so the backend may fall back to Content-Length while an intermediary treats the message as chunked.

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.

Affected versions of the nbconvert package are vulnerable to Uncontrolled Search Path Element due to resolving the inkscape executable on Windows using a search order that includes the current working directory. In nbconvert/preprocessors/svg2pdf.py, the PDF conversion flow for notebooks with SVG outputs locates and executes inkscape without a fully qualified path, allowing a local inkscape.bat to be selected and run.

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq

Ipywidgets 8.0.0 sanitizes descriptions by default.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Ipywidgets 8.0.0rc2 makes descriptions plaintext by default for security.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Jupyter Core is a package for the core common functionality of Jupyter projects. Jupyter Core prior to version 4.11.2 contains an arbitrary code execution vulnerability in 'jupyter_core' that stems from 'jupyter_core' executing untrusted files in CWD. This vulnerability allows one user to run code as another.

Prompt-toolkit 3.0.13 fixes a race condition in `ThreadedHistory` which could lead to a deadlock. 
https://github.com/prompt-toolkit/python-prompt-toolkit/commit/99092a8c6d4b411645ac4b84d504e5226e7eebb8#diff-48c0ff10dc3990285d19b3f54e6bfec763089ba1229dc6f9e88463a1046adad7R163

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Bleach 3.3.0 includes a fix for CVE-2021-23980: A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.

Affected versions of the Bleach package are vulnerable to Cross-site Scripting (XSS) due to improper handling of whitelisted tags in the bleach.clean function. The vulnerability exists because the bleach.clean function allows certain raw tags, such as "noscript" and "script", to be whitelisted, which can lead to unintended HTML mutations. An attacker can exploit this by crafting malicious HTML content that includes these tags, potentially executing arbitrary scripts in the context of the user's browser session.

Bleach 3.1.2 includes a fix for CVE-2020-6816: Mutation XSS via whitelisted math or svg and RCDATA tag with strip=False.
https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743

Bleach 3.1.4 includes a fix for CVE-2020-6817: bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).

Ipython versions 8.0.1, 7.31.1, 7.16.3 and 5.11 include a fix for CVE-2022-21699: Affected versions are subject to an arbitrary code execution vulnerability achieved by not properly managing cross user temporary files. This vulnerability allows one user to run code as another on the same machine.
https://github.com/ipython/ipython/security/advisories/GHSA-pq7m-3gw7-gq5x

IPython 8.10.0 includes a fix for CVE-2023-24816: Versions prior to 8.10.0 are subject to a command injection vulnerability with very specific prerequisites. This vulnerability requires that the function 'IPython.utils.terminal.set_term_title' be called on Windows in a Python environment where ctypes is not available. The dependency on 'ctypes' in 'IPython.utils._process_win32' prevents the vulnerable code from ever being reached in the ipython binary. However, as a library that could be used by another tool 'set_term_title' could be called and hence introduce a vulnerability. If an attacker get untrusted input to an instance of this function they would be able to inject shell commands as current process and limited to the scope of the current process. As a workaround, users should ensure that any calls to the 'IPython.utils.terminal.set_term_title' function are done with trusted or filtered input.
https://github.com/ipython/ipython/security/advisories/GHSA-29gw-9793-fvw7

Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.

An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker who controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the '_punctuation_re regex' operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, `/`, `>`, or `=`, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the `xmlattr` filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting _values_ as user input continues to be safe.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous.

When Tornado receives a request with two Transfer-Encoding: chunked headers, it ignores them both. This enables request smuggling when Tornado is deployed behind a proxy server that emits such requests. Pound does this.

Summary: Tornado's interpretation of symbols `-`, `+`, and `_` within chunk lengths and 'Content-Length' values contradicts the HTTP RFCs stipulations, potentially creating an avenue for request smuggling. This issue is generally found when Tornado operates behind specific proxies that understand these non-standard characters diversely, mostly observed in earlier versions of 'haproxy'; however, the latest version remains unaffected.

Details: Tornado utilizes the 'int' constructor to decipher the 'Content-Length' headers and chunk lengths in the locations mentioned below:

`tornado/http1connection.py:445`
Python3 code: self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`
Python3 code: content_length = int(headers["Content-Length"])

`tornado/http1connection.py:671`
Python3 code: chunk_len = int(chunk_len_str.strip(), 16)

Notably, though the equation `int("0_0")` equates to `int("+0")`, `int("-0")`, and `int("0")`, using the 'int' constructor as a strategy for validating and parsing strings containing ASCII digits only is proven inadequate.

Tornado web framework affected versions contain a performance vulnerability in their HTTP cookie parser. When processing specially crafted malicious cookie headers, the parser's algorithm can exhibit quadratic time complexity. Since this parsing happens in the main event loop thread, it can cause the server to become unresponsive and block the processing of other incoming requests due to excessive CPU usage.

Tornado 6.3.2 includes a fix for CVE-2023-28370: Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

Tornado’s curl_httpclient.CurlAsyncHTTPClient class is vulnerable to CRLF (carriage return/line feed) injection in the request headers.

Jupyter Notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.12, authenticated requests to the notebook server with `ContentsManager.allow_hidden = False` only prevented listing the contents of hidden directories, not accessing individual hidden files or files in hidden directories (i.e. hidden files were 'hidden' but not 'inaccessible'). This could lead to notebook configurations allowing authenticated access to files that may reasonably be expected to be disallowed. Because fully authenticated requests are required, this is of relatively low impact. But if a server's root directory contains sensitive files whose only protection from the server is being hidden (e.g. `~/.ssh` while serving $HOME), then any authenticated requests could access files if their names are guessable. Such contexts also necessarily have full access to the server and therefore execution permissions, which also generally grants access to all the same files. So this does not generally result in any privilege escalation or increase in information access, only an additional, unintended means by which the files could be accessed. Version 6.4.12 contains a patch for this issue. There are currently no known workarounds.
https://github.com/jupyter/notebook/security/advisories/GHSA-v7vq-3x77-87vg

The Jupyter notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.9, unauthorized actors can access sensitive information from server logs. Anytime a 5xx error is triggered, the auth cookie and other header values are recorded in Jupyter server logs by default. Considering these logs do not require root access, an attacker can monitor these logs, steal sensitive auth/cookie information, and gain access to the Jupyter server. Jupyter notebook version 6.4.x contains a patch for this issue. There are currently no known workarounds.

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

Notebook 6.1.5 fixes open redirect vulnerability 'GHSA-c7vm-f5p4-8fqh'. See: CVE-2020-26215.
https://github.com/advisories/GHSA-c7vm-f5p4-8fqh
https://github.com/jupyter/notebook/pull/5874

Notebook 6.0.2 updates its dependency 'JQuery' to v3.5.0 to include a security fix.

Pygments 2.15.0 includes a fix for CVE-2022-40896: The regular expressions used when parsing Smithy, SQL/SQL+Jinja, and Java properties files were discovered to be vulnerable. As a result, pygmentizing a maliciously-crafted file of these kinds would have resulted in high resources consumption or crashing of the application.
https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages-part-2

Pygments 2.7.4 includes a fix for CVE-2021-20270: An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Pygments 2.7.4 includes a fix for CVE-2021-27291: In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.

Gunicorn 20.0.1 fixes chunked encoding support to prevent http request smuggling attacks.
https://github.com/benoitc/gunicorn/issues/2176
https://github.com/p4k03n4t0r/http-request-smuggling#request-smuggling-using-mitmproxy-and-gunicorn

Affected versions of the gunicorn package are vulnerable to HTTP Request/Response Smuggling due to improper validation of the Transfer-Encoding header that enables a TE.CL desynchronisation condition. Gunicorn’s HTTP parser does not consistently enforce RFC semantics when parsing conflicting or unsupported request framing—such as messages containing both Transfer-Encoding and Content-Length—so the backend may fall back to Content-Length while an intermediary treats the message as chunked.

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.

Affected versions of the nbconvert package are vulnerable to Uncontrolled Search Path Element due to resolving the inkscape executable on Windows using a search order that includes the current working directory. In nbconvert/preprocessors/svg2pdf.py, the PDF conversion flow for notebooks with SVG outputs locates and executes inkscape without a fully qualified path, allowing a local inkscape.bat to be selected and run.

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq

Ipywidgets 8.0.0 sanitizes descriptions by default.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Ipywidgets 8.0.0rc2 makes descriptions plaintext by default for security.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Jupyter Core is a package for the core common functionality of Jupyter projects. Jupyter Core prior to version 4.11.2 contains an arbitrary code execution vulnerability in 'jupyter_core' that stems from 'jupyter_core' executing untrusted files in CWD. This vulnerability allows one user to run code as another.

Prompt-toolkit 3.0.13 fixes a race condition in `ThreadedHistory` which could lead to a deadlock. 
https://github.com/prompt-toolkit/python-prompt-toolkit/commit/99092a8c6d4b411645ac4b84d504e5226e7eebb8#diff-48c0ff10dc3990285d19b3f54e6bfec763089ba1229dc6f9e88463a1046adad7R163

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Bleach 3.3.0 includes a fix for CVE-2021-23980: A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.

Affected versions of the Bleach package are vulnerable to Cross-site Scripting (XSS) due to improper handling of whitelisted tags in the bleach.clean function. The vulnerability exists because the bleach.clean function allows certain raw tags, such as "noscript" and "script", to be whitelisted, which can lead to unintended HTML mutations. An attacker can exploit this by crafting malicious HTML content that includes these tags, potentially executing arbitrary scripts in the context of the user's browser session.

Bleach 3.1.2 includes a fix for CVE-2020-6816: Mutation XSS via whitelisted math or svg and RCDATA tag with strip=False.
https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743

Bleach 3.1.4 includes a fix for CVE-2020-6817: bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).

Ipython versions 8.0.1, 7.31.1, 7.16.3 and 5.11 include a fix for CVE-2022-21699: Affected versions are subject to an arbitrary code execution vulnerability achieved by not properly managing cross user temporary files. This vulnerability allows one user to run code as another on the same machine.
https://github.com/ipython/ipython/security/advisories/GHSA-pq7m-3gw7-gq5x

IPython 8.10.0 includes a fix for CVE-2023-24816: Versions prior to 8.10.0 are subject to a command injection vulnerability with very specific prerequisites. This vulnerability requires that the function 'IPython.utils.terminal.set_term_title' be called on Windows in a Python environment where ctypes is not available. The dependency on 'ctypes' in 'IPython.utils._process_win32' prevents the vulnerable code from ever being reached in the ipython binary. However, as a library that could be used by another tool 'set_term_title' could be called and hence introduce a vulnerability. If an attacker get untrusted input to an instance of this function they would be able to inject shell commands as current process and limited to the scope of the current process. As a workaround, users should ensure that any calls to the 'IPython.utils.terminal.set_term_title' function are done with trusted or filtered input.
https://github.com/ipython/ipython/security/advisories/GHSA-29gw-9793-fvw7

Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.

An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker who controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the '_punctuation_re regex' operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, `/`, `>`, or `=`, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the `xmlattr` filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting _values_ as user input continues to be safe.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous.

When Tornado receives a request with two Transfer-Encoding: chunked headers, it ignores them both. This enables request smuggling when Tornado is deployed behind a proxy server that emits such requests. Pound does this.

Summary: Tornado's interpretation of symbols `-`, `+`, and `_` within chunk lengths and 'Content-Length' values contradicts the HTTP RFCs stipulations, potentially creating an avenue for request smuggling. This issue is generally found when Tornado operates behind specific proxies that understand these non-standard characters diversely, mostly observed in earlier versions of 'haproxy'; however, the latest version remains unaffected.

Details: Tornado utilizes the 'int' constructor to decipher the 'Content-Length' headers and chunk lengths in the locations mentioned below:

`tornado/http1connection.py:445`
Python3 code: self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`
Python3 code: content_length = int(headers["Content-Length"])

`tornado/http1connection.py:671`
Python3 code: chunk_len = int(chunk_len_str.strip(), 16)

Notably, though the equation `int("0_0")` equates to `int("+0")`, `int("-0")`, and `int("0")`, using the 'int' constructor as a strategy for validating and parsing strings containing ASCII digits only is proven inadequate.

Tornado web framework affected versions contain a performance vulnerability in their HTTP cookie parser. When processing specially crafted malicious cookie headers, the parser's algorithm can exhibit quadratic time complexity. Since this parsing happens in the main event loop thread, it can cause the server to become unresponsive and block the processing of other incoming requests due to excessive CPU usage.

Tornado 6.3.2 includes a fix for CVE-2023-28370: Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

Tornado’s curl_httpclient.CurlAsyncHTTPClient class is vulnerable to CRLF (carriage return/line feed) injection in the request headers.

Jupyter Notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.12, authenticated requests to the notebook server with `ContentsManager.allow_hidden = False` only prevented listing the contents of hidden directories, not accessing individual hidden files or files in hidden directories (i.e. hidden files were 'hidden' but not 'inaccessible'). This could lead to notebook configurations allowing authenticated access to files that may reasonably be expected to be disallowed. Because fully authenticated requests are required, this is of relatively low impact. But if a server's root directory contains sensitive files whose only protection from the server is being hidden (e.g. `~/.ssh` while serving $HOME), then any authenticated requests could access files if their names are guessable. Such contexts also necessarily have full access to the server and therefore execution permissions, which also generally grants access to all the same files. So this does not generally result in any privilege escalation or increase in information access, only an additional, unintended means by which the files could be accessed. Version 6.4.12 contains a patch for this issue. There are currently no known workarounds.
https://github.com/jupyter/notebook/security/advisories/GHSA-v7vq-3x77-87vg

The Jupyter notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.9, unauthorized actors can access sensitive information from server logs. Anytime a 5xx error is triggered, the auth cookie and other header values are recorded in Jupyter server logs by default. Considering these logs do not require root access, an attacker can monitor these logs, steal sensitive auth/cookie information, and gain access to the Jupyter server. Jupyter notebook version 6.4.x contains a patch for this issue. There are currently no known workarounds.

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

Notebook 6.1.5 fixes open redirect vulnerability 'GHSA-c7vm-f5p4-8fqh'. See: CVE-2020-26215.
https://github.com/advisories/GHSA-c7vm-f5p4-8fqh
https://github.com/jupyter/notebook/pull/5874

Notebook 6.0.2 updates its dependency 'JQuery' to v3.5.0 to include a security fix.

Pygments 2.15.0 includes a fix for CVE-2022-40896: The regular expressions used when parsing Smithy, SQL/SQL+Jinja, and Java properties files were discovered to be vulnerable. As a result, pygmentizing a maliciously-crafted file of these kinds would have resulted in high resources consumption or crashing of the application.
https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages-part-2

Pygments 2.7.4 includes a fix for CVE-2021-20270: An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Pygments 2.7.4 includes a fix for CVE-2021-27291: In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.

Gunicorn 20.0.1 fixes chunked encoding support to prevent http request smuggling attacks.
https://github.com/benoitc/gunicorn/issues/2176
https://github.com/p4k03n4t0r/http-request-smuggling#request-smuggling-using-mitmproxy-and-gunicorn

Affected versions of the gunicorn package are vulnerable to HTTP Request/Response Smuggling due to improper validation of the Transfer-Encoding header that enables a TE.CL desynchronisation condition. Gunicorn’s HTTP parser does not consistently enforce RFC semantics when parsing conflicting or unsupported request framing—such as messages containing both Transfer-Encoding and Content-Length—so the backend may fall back to Content-Length while an intermediary treats the message as chunked.

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.

Affected versions of the nbconvert package are vulnerable to Uncontrolled Search Path Element due to resolving the inkscape executable on Windows using a search order that includes the current working directory. In nbconvert/preprocessors/svg2pdf.py, the PDF conversion flow for notebooks with SVG outputs locates and executes inkscape without a fully qualified path, allowing a local inkscape.bat to be selected and run.

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq

Ipywidgets 8.0.0 sanitizes descriptions by default.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Ipywidgets 8.0.0rc2 makes descriptions plaintext by default for security.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Jupyter Core is a package for the core common functionality of Jupyter projects. Jupyter Core prior to version 4.11.2 contains an arbitrary code execution vulnerability in 'jupyter_core' that stems from 'jupyter_core' executing untrusted files in CWD. This vulnerability allows one user to run code as another.

Prompt-toolkit 3.0.13 fixes a race condition in `ThreadedHistory` which could lead to a deadlock. 
https://github.com/prompt-toolkit/python-prompt-toolkit/commit/99092a8c6d4b411645ac4b84d504e5226e7eebb8#diff-48c0ff10dc3990285d19b3f54e6bfec763089ba1229dc6f9e88463a1046adad7R163

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Bleach 3.3.0 includes a fix for CVE-2021-23980: A mutation XSS affects users calling bleach.clean with all of: svg or math in the allowed tags p or br in allowed tags style, title, noscript, script, textarea, noframes, iframe, or xmp in allowed tags the keyword argument strip_comments=False Note: none of the above tags are in the default allowed tags and strip_comments defaults to True.

Affected versions of the Bleach package are vulnerable to Cross-site Scripting (XSS) due to improper handling of whitelisted tags in the bleach.clean function. The vulnerability exists because the bleach.clean function allows certain raw tags, such as "noscript" and "script", to be whitelisted, which can lead to unintended HTML mutations. An attacker can exploit this by crafting malicious HTML content that includes these tags, potentially executing arbitrary scripts in the context of the user's browser session.

Bleach 3.1.2 includes a fix for CVE-2020-6816: Mutation XSS via whitelisted math or svg and RCDATA tag with strip=False.
https://github.com/mozilla/bleach/security/advisories/GHSA-m6xf-fq7q-8743

Bleach 3.1.4 includes a fix for CVE-2020-6817: bleach.clean behavior parsing style attributes could result in a regular expression denial of service (ReDoS). Calls to bleach.clean with an allowed tag with an allowed style attribute are vulnerable to ReDoS. For example, bleach.clean(..., attributes={'a': ['style']}).

Ipython versions 8.0.1, 7.31.1, 7.16.3 and 5.11 include a fix for CVE-2022-21699: Affected versions are subject to an arbitrary code execution vulnerability achieved by not properly managing cross user temporary files. This vulnerability allows one user to run code as another on the same machine.
https://github.com/ipython/ipython/security/advisories/GHSA-pq7m-3gw7-gq5x

IPython 8.10.0 includes a fix for CVE-2023-24816: Versions prior to 8.10.0 are subject to a command injection vulnerability with very specific prerequisites. This vulnerability requires that the function 'IPython.utils.terminal.set_term_title' be called on Windows in a Python environment where ctypes is not available. The dependency on 'ctypes' in 'IPython.utils._process_win32' prevents the vulnerable code from ever being reached in the ipython binary. However, as a library that could be used by another tool 'set_term_title' could be called and hence introduce a vulnerability. If an attacker get untrusted input to an instance of this function they would be able to inject shell commands as current process and limited to the scope of the current process. As a workaround, users should ensure that any calls to the 'IPython.utils.terminal.set_term_title' function are done with trusted or filtered input.
https://github.com/ipython/ipython/security/advisories/GHSA-29gw-9793-fvw7

Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.

An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker who controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the '_punctuation_re regex' operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, `/`, `>`, or `=`, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the `xmlattr` filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting _values_ as user input continues to be safe.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous.

When Tornado receives a request with two Transfer-Encoding: chunked headers, it ignores them both. This enables request smuggling when Tornado is deployed behind a proxy server that emits such requests. Pound does this.

Summary: Tornado's interpretation of symbols `-`, `+`, and `_` within chunk lengths and 'Content-Length' values contradicts the HTTP RFCs stipulations, potentially creating an avenue for request smuggling. This issue is generally found when Tornado operates behind specific proxies that understand these non-standard characters diversely, mostly observed in earlier versions of 'haproxy'; however, the latest version remains unaffected.

Details: Tornado utilizes the 'int' constructor to decipher the 'Content-Length' headers and chunk lengths in the locations mentioned below:

`tornado/http1connection.py:445`
Python3 code: self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`
Python3 code: content_length = int(headers["Content-Length"])

`tornado/http1connection.py:671`
Python3 code: chunk_len = int(chunk_len_str.strip(), 16)

Notably, though the equation `int("0_0")` equates to `int("+0")`, `int("-0")`, and `int("0")`, using the 'int' constructor as a strategy for validating and parsing strings containing ASCII digits only is proven inadequate.

Tornado web framework affected versions contain a performance vulnerability in their HTTP cookie parser. When processing specially crafted malicious cookie headers, the parser's algorithm can exhibit quadratic time complexity. Since this parsing happens in the main event loop thread, it can cause the server to become unresponsive and block the processing of other incoming requests due to excessive CPU usage.

Tornado 6.3.2 includes a fix for CVE-2023-28370: Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

Tornado’s curl_httpclient.CurlAsyncHTTPClient class is vulnerable to CRLF (carriage return/line feed) injection in the request headers.

Jupyter Notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.12, authenticated requests to the notebook server with `ContentsManager.allow_hidden = False` only prevented listing the contents of hidden directories, not accessing individual hidden files or files in hidden directories (i.e. hidden files were 'hidden' but not 'inaccessible'). This could lead to notebook configurations allowing authenticated access to files that may reasonably be expected to be disallowed. Because fully authenticated requests are required, this is of relatively low impact. But if a server's root directory contains sensitive files whose only protection from the server is being hidden (e.g. `~/.ssh` while serving $HOME), then any authenticated requests could access files if their names are guessable. Such contexts also necessarily have full access to the server and therefore execution permissions, which also generally grants access to all the same files. So this does not generally result in any privilege escalation or increase in information access, only an additional, unintended means by which the files could be accessed. Version 6.4.12 contains a patch for this issue. There are currently no known workarounds.
https://github.com/jupyter/notebook/security/advisories/GHSA-v7vq-3x77-87vg

The Jupyter notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.9, unauthorized actors can access sensitive information from server logs. Anytime a 5xx error is triggered, the auth cookie and other header values are recorded in Jupyter server logs by default. Considering these logs do not require root access, an attacker can monitor these logs, steal sensitive auth/cookie information, and gain access to the Jupyter server. Jupyter notebook version 6.4.x contains a patch for this issue. There are currently no known workarounds.

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

Notebook 6.1.5 fixes open redirect vulnerability 'GHSA-c7vm-f5p4-8fqh'. See: CVE-2020-26215.
https://github.com/advisories/GHSA-c7vm-f5p4-8fqh
https://github.com/jupyter/notebook/pull/5874

Notebook 6.0.2 updates its dependency 'JQuery' to v3.5.0 to include a security fix.

Pygments 2.15.0 includes a fix for CVE-2022-40896: The regular expressions used when parsing Smithy, SQL/SQL+Jinja, and Java properties files were discovered to be vulnerable. As a result, pygmentizing a maliciously-crafted file of these kinds would have resulted in high resources consumption or crashing of the application.
https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages-part-2

Pygments 2.7.4 includes a fix for CVE-2021-20270: An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Pygments 2.7.4 includes a fix for CVE-2021-27291: In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.

Gunicorn 20.0.1 fixes chunked encoding support to prevent http request smuggling attacks.
https://github.com/benoitc/gunicorn/issues/2176
https://github.com/p4k03n4t0r/http-request-smuggling#request-smuggling-using-mitmproxy-and-gunicorn

Affected versions of the gunicorn package are vulnerable to HTTP Request/Response Smuggling due to improper validation of the Transfer-Encoding header that enables a TE.CL desynchronisation condition. Gunicorn’s HTTP parser does not consistently enforce RFC semantics when parsing conflicting or unsupported request framing—such as messages containing both Transfer-Encoding and Content-Length—so the backend may fall back to Content-Length while an intermediary treats the message as chunked.

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.

Affected versions of the nbconvert package are vulnerable to Uncontrolled Search Path Element due to resolving the inkscape executable on Windows using a search order that includes the current working directory. In nbconvert/preprocessors/svg2pdf.py, the PDF conversion flow for notebooks with SVG outputs locates and executes inkscape without a fully qualified path, allowing a local inkscape.bat to be selected and run.

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq

Jupyter Core is a package for the core common functionality of Jupyter projects. Jupyter Core prior to version 4.11.2 contains an arbitrary code execution vulnerability in 'jupyter_core' that stems from 'jupyter_core' executing untrusted files in CWD. This vulnerability allows one user to run code as another.

Prompt-toolkit 3.0.13 fixes a race condition in `ThreadedHistory` which could lead to a deadlock. 
https://github.com/prompt-toolkit/python-prompt-toolkit/commit/99092a8c6d4b411645ac4b84d504e5226e7eebb8#diff-48c0ff10dc3990285d19b3f54e6bfec763089ba1229dc6f9e88463a1046adad7R163

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Ipython versions 8.0.1, 7.31.1, 7.16.3 and 5.11 include a fix for CVE-2022-21699: Affected versions are subject to an arbitrary code execution vulnerability achieved by not properly managing cross user temporary files. This vulnerability allows one user to run code as another on the same machine.
https://github.com/ipython/ipython/security/advisories/GHSA-pq7m-3gw7-gq5x

IPython 8.10.0 includes a fix for CVE-2023-24816: Versions prior to 8.10.0 are subject to a command injection vulnerability with very specific prerequisites. This vulnerability requires that the function 'IPython.utils.terminal.set_term_title' be called on Windows in a Python environment where ctypes is not available. The dependency on 'ctypes' in 'IPython.utils._process_win32' prevents the vulnerable code from ever being reached in the ipython binary. However, as a library that could be used by another tool 'set_term_title' could be called and hence introduce a vulnerability. If an attacker get untrusted input to an instance of this function they would be able to inject shell commands as current process and limited to the scope of the current process. As a workaround, users should ensure that any calls to the 'IPython.utils.terminal.set_term_title' function are done with trusted or filtered input.
https://github.com/ipython/ipython/security/advisories/GHSA-29gw-9793-fvw7

Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.

An oversight in how the Jinja sandboxed environment detects calls to str.format allows an attacker who controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to store a reference to a malicious string's format method, then pass that to a filter that calls it. No such filters are built-in to Jinja, but could be present through custom filters in an application. After the fix, such indirect calls are also handled by the sandbox.

This affects the package jinja2 from 0.0.0 and before 2.11.3. The ReDoS vulnerability is mainly due to the '_punctuation_re regex' operator and its use of multiple wildcards. The last wildcard is the most exploitable as it searches for trailing punctuation. This issue can be mitigated by Markdown to format user content instead of the urlize filter, or by implementing request timeouts and limiting process memory.

Jinja is an extensible templating engine. The `xmlattr` filter in affected versions of Jinja accepts keys containing non-attribute characters. XML/HTML attributes cannot contain spaces, `/`, `>`, or `=`, as each would then be interpreted as starting a separate attribute. If an application accepts keys (as opposed to only values) as user input, and renders these in pages that other users see as well, an attacker could use this to inject other attributes and perform XSS. The fix for CVE-2024-22195 only addressed spaces but not other characters. Accepting keys as user input is now explicitly considered an unintended use case of the `xmlattr` filter, and code that does so without otherwise validating the input should be flagged as insecure, regardless of Jinja version. Accepting _values_ as user input continues to be safe.

Jinja is an extensible templating engine. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template, potentially leading to Cross-Site Scripting (XSS). The Jinja `xmlattr` filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous.

When Tornado receives a request with two Transfer-Encoding: chunked headers, it ignores them both. This enables request smuggling when Tornado is deployed behind a proxy server that emits such requests. Pound does this.

Summary: Tornado's interpretation of symbols `-`, `+`, and `_` within chunk lengths and 'Content-Length' values contradicts the HTTP RFCs stipulations, potentially creating an avenue for request smuggling. This issue is generally found when Tornado operates behind specific proxies that understand these non-standard characters diversely, mostly observed in earlier versions of 'haproxy'; however, the latest version remains unaffected.

Details: Tornado utilizes the 'int' constructor to decipher the 'Content-Length' headers and chunk lengths in the locations mentioned below:

`tornado/http1connection.py:445`
Python3 code: self._expected_content_remaining = int(headers["Content-Length"])

`tornado/http1connection.py:621`
Python3 code: content_length = int(headers["Content-Length"])

`tornado/http1connection.py:671`
Python3 code: chunk_len = int(chunk_len_str.strip(), 16)

Notably, though the equation `int("0_0")` equates to `int("+0")`, `int("-0")`, and `int("0")`, using the 'int' constructor as a strategy for validating and parsing strings containing ASCII digits only is proven inadequate.

Tornado web framework affected versions contain a performance vulnerability in their HTTP cookie parser. When processing specially crafted malicious cookie headers, the parser's algorithm can exhibit quadratic time complexity. Since this parsing happens in the main event loop thread, it can cause the server to become unresponsive and block the processing of other incoming requests due to excessive CPU usage.

Tornado 6.3.2 includes a fix for CVE-2023-28370: Open redirect vulnerability in Tornado versions 6.3.1 and earlier allows a remote unauthenticated attacker to redirect a user to an arbitrary web site and conduct a phishing attack by having user access a specially crafted URL.

Tornado’s curl_httpclient.CurlAsyncHTTPClient class is vulnerable to CRLF (carriage return/line feed) injection in the request headers.

Jupyter Notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.12, authenticated requests to the notebook server with `ContentsManager.allow_hidden = False` only prevented listing the contents of hidden directories, not accessing individual hidden files or files in hidden directories (i.e. hidden files were 'hidden' but not 'inaccessible'). This could lead to notebook configurations allowing authenticated access to files that may reasonably be expected to be disallowed. Because fully authenticated requests are required, this is of relatively low impact. But if a server's root directory contains sensitive files whose only protection from the server is being hidden (e.g. `~/.ssh` while serving $HOME), then any authenticated requests could access files if their names are guessable. Such contexts also necessarily have full access to the server and therefore execution permissions, which also generally grants access to all the same files. So this does not generally result in any privilege escalation or increase in information access, only an additional, unintended means by which the files could be accessed. Version 6.4.12 contains a patch for this issue. There are currently no known workarounds.
https://github.com/jupyter/notebook/security/advisories/GHSA-v7vq-3x77-87vg

The Jupyter notebook is a web-based notebook environment for interactive computing. Prior to version 6.4.9, unauthorized actors can access sensitive information from server logs. Anytime a 5xx error is triggered, the auth cookie and other header values are recorded in Jupyter server logs by default. Considering these logs do not require root access, an attacker can monitor these logs, steal sensitive auth/cookie information, and gain access to the Jupyter server. Jupyter notebook version 6.4.x contains a patch for this issue. There are currently no known workarounds.

The Jupyter notebook is a web-based notebook environment for interactive computing. In affected versions untrusted notebook can execute code on load. Jupyter Notebook uses a deprecated version of Google Caja to sanitize user inputs. A public Caja bypass can be used to trigger an XSS when a victim opens a malicious ipynb document in Jupyter Notebook. The XSS allows an attacker to execute arbitrary code on the victim computer using Jupyter APIs.

Notebook 6.1.5 fixes open redirect vulnerability 'GHSA-c7vm-f5p4-8fqh'. See: CVE-2020-26215.
https://github.com/advisories/GHSA-c7vm-f5p4-8fqh
https://github.com/jupyter/notebook/pull/5874

Notebook 6.0.2 updates its dependency 'JQuery' to v3.5.0 to include a security fix.

Pygments 2.15.0 includes a fix for CVE-2022-40896: The regular expressions used when parsing Smithy, SQL/SQL+Jinja, and Java properties files were discovered to be vulnerable. As a result, pygmentizing a maliciously-crafted file of these kinds would have resulted in high resources consumption or crashing of the application.
https://pyup.io/posts/pyup-discovers-redos-vulnerabilities-in-top-python-packages-part-2

Pygments 2.7.4 includes a fix for CVE-2021-20270: An infinite loop in SMLLexer in Pygments versions 1.5 to 2.7.3 may lead to denial of service when performing syntax highlighting of a Standard ML (SML) source file, as demonstrated by input that only contains the "exception" keyword.

Pygments 2.7.4 includes a fix for CVE-2021-27291: In pygments 1.1+, fixed in 2.7.4, the lexers used to parse programming languages rely heavily on regular expressions. Some of the regular expressions have exponential or cubic worst-case complexity and are vulnerable to ReDoS. By crafting malicious input, an attacker can cause a denial of service.

Gunicorn 20.0.1 fixes chunked encoding support to prevent http request smuggling attacks.
https://github.com/benoitc/gunicorn/issues/2176
https://github.com/p4k03n4t0r/http-request-smuggling#request-smuggling-using-mitmproxy-and-gunicorn

Affected versions of the gunicorn package are vulnerable to HTTP Request/Response Smuggling due to improper validation of the Transfer-Encoding header that enables a TE.CL desynchronisation condition. Gunicorn’s HTTP parser does not consistently enforce RFC semantics when parsing conflicting or unsupported request framing—such as messages containing both Transfer-Encoding and Content-Length—so the backend may fall back to Content-Length while an intermediary treats the message as chunked.

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure.

Affected versions of the nbconvert package are vulnerable to Uncontrolled Search Path Element due to resolving the inkscape executable on Windows using a search order that includes the current working directory. In nbconvert/preprocessors/svg2pdf.py, the PDF conversion flow for notebooks with SVG outputs locates and executes inkscape without a fully qualified path, allowing a local inkscape.bat to be selected and run.

The GitHub Security Lab discovered sixteen ways to exploit a cross-site scripting vulnerability in nbconvert. When using nbconvert to generate an HTML version of a user-controllable notebook, it is possible to inject arbitrary HTML which may lead to cross-site scripting (XSS) vulnerabilities if these HTML notebooks are served by a web server (eg: nbviewer).
https://github.com/jupyter/nbconvert/security/advisories/GHSA-9jmq-rx5f-8jwq

Ipywidgets 8.0.0 sanitizes descriptions by default.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Ipywidgets 8.0.0rc2 makes descriptions plaintext by default for security.
https://github.com/jupyter-widgets/ipywidgets/pull/2785

Jupyter Core is a package for the core common functionality of Jupyter projects. Jupyter Core prior to version 4.11.2 contains an arbitrary code execution vulnerability in 'jupyter_core' that stems from 'jupyter_core' executing untrusted files in CWD. This vulnerability allows one user to run code as another.

Prompt-toolkit 3.0.13 fixes a race condition in `ThreadedHistory` which could lead to a deadlock. 
https://github.com/prompt-toolkit/python-prompt-toolkit/commit/99092a8c6d4b411645ac4b84d504e5226e7eebb8#diff-48c0ff10dc3990285d19b3f54e6bfec763089ba1229dc6f9e88463a1046adad7R163

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.

Affected versions of Django are vulnerable to potential Denial of Service via certain inputs with a very large number of Unicode characters in django.utils.encoding.uri_to_iri().

Django 1.11.23, 2.1.11 and 2.2.4 includes a fix for CVE-2019-14235: If passed certain inputs, django.utils.encoding.uri_to_iri could lead to significant memory usage due to a recursion when repercent-encoding invalid UTF-8 octet sequences.

Django affected versions are vulnerable to a potential SQL injection in the HasKey(lhs, rhs) lookup on Oracle databases. The vulnerability arises when untrusted data is directly used as the lhs value in the django.db.models.fields.json.HasKey lookup. However, applications using the jsonfield.has_key lookup with the __ syntax remain unaffected by this issue.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45452: Storage.save in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1 allows directory traversal if crafted filenames are directly passed to it.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are vulnerable to a potential denial-of-service (DoS) attack in the `django.utils.html.strip_tags()` method. The vulnerability occurs when the `strip_tags()` method or the `striptags` template filter processes inputs containing large sequences of nested, incomplete HTML entities.

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to quadratic time complexity during HTML parsing in text truncation methods. The django.utils.text.Truncator.chars() and Truncator.words() methods (with html=True), as well as the truncatechars_html and truncatewords_html template filters, exhibit quadratic time complexity when processing inputs containing a large number of unmatched HTML end tags.

Affected versions of the Django package are vulnerable to Information Disclosure (Timing Attack) due to non-constant-time comparison in the mod_wsgi authentication handler. The django.contrib.auth.handlers.modwsgi.check_password() function does not perform user existence checks in constant time, allowing response timing differences to reveal whether usernames exist.

The {% debug %} template tag in Django 2.2 before 2.2.27, 3.2 before 3.2.12, and 4.0 before 4.0.2 does not properly encode the current context. This may lead to XSS.

Django fixes a potential denial-of-service vulnerability in XML ``Deserializer``.

An issue was discovered in Django 5.2 before 5.2.3, 5.1 before 5.1.11, and 4.2 before 4.2.23. Internal HTTP response logging does not escape request.path, which allows remote attackers to potentially manipulate log output via crafted URLs. This may lead to log injection or forgery when logs are viewed in terminals or processed by external systems.

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45116: An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. Due to leveraging the Django Template Language's variable resolution logic, the dictsort template filter was potentially vulnerable to information disclosure, or an unintended method call, if passed a suitably crafted key.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases

Django versions 2.2.25, 3.1.14 and 3.2.10 include a fix for CVE-2021-44420: In Django 2.2 before 2.2.25, 3.1 before 3.1.14, and 3.2 before 3.2.10, HTTP requests for URLs with trailing newlines could bypass upstream access control based on URL paths.
https://www.djangoproject.com/weblog/2021/dec/07/security-releases/

Django 2.2.26, 3.2.11 and 4.0.1 include a fix for CVE-2021-45115: UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.
https://www.djangoproject.com/weblog/2022/jan/04/security-releases/

Affected versions of Django are affected by a potential denial-of-service vulnerability in the django.utils.html.urlize() function. The urlize and urlizetrunc template filters were susceptible to a denial-of-service attack via certain inputs containing many brackets. An attacker could exploit this vulnerability to cause significant delays or crashes in the affected application.

Affected versions of Django are affected by a directory-traversal vulnerability in the Storage.save() method. Derived classes of the django.core.files.storage.Storage base class that overrides the generate_filename() method without replicating the file path validations existing in the parent class could allow for directory traversal via certain inputs when calling save(). This could enable an attacker to manipulate file paths and access unintended directories.

Django 2.1.15 and 2.2.8 includes a fix for CVE-2019-19118: A Django model admin displaying inline related models, where the user has view-only permissions to a parent model but edit permissions to the inline model, would be presented with an editing UI, allowing POST requests, for updating the inline model. Directly editing the view-only parent model was not possible, but the parent model's save() method was called, triggering potential side effects, and causing pre and post-save signal handlers to be invoked. To resolve this, the Django admin is adjusted to require edit permissions on the parent model in order for inline models to be editable.

Django 1.11.28, 2.2.10 and 3.0.3 include a fix for CVE-2020-7471: SQL Injection if untrusted data is used as a StringAgg delimiter (e.g., in Django applications that offer downloads of data as a series of rows with a user-specified column delimiter). By passing a suitably crafted delimiter to a contrib.postgres.aggregates.StringAgg instance, it was possible to break escaping and inject malicious SQL.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14234: Due to an error in shallow key transformation, key and index lookups for django.contrib.postgres.fields.JSONField, and key lookups for django.contrib.postgres.fields.HStoreField, were subject to SQL injection. This could, for example, be exploited via crafted use of "OR 1=1" in a key or index name to return all records, using a suitably crafted dictionary, with dictionary expansion, as the **kwargs passed to the QuerySet.filter() function.

Affected versions of Django has a potential SQL injection vulnerability in the QuerySet.values() and QuerySet.values_list() methods. When used on models with a JSONField, these methods are susceptible to SQL injection through column aliases if a crafted JSON object key is passed as an argument.

Django versions 2.1.9 and 2.2.2 include a patched bundled jQuery version to avoid a Prototype Pollution vulnerability.

A security vulnerability has been discovered in certain versions of Django, affecting the password reset functionality. The PasswordResetForm class in django.contrib.auth.forms inadvertently allowed attackers to enumerate user email addresses by exploiting unhandled exceptions during the email sending process. This could be done by issuing password reset requests and observing the responses. Django has implemented a fix where these exceptions are now caught and logged using the django.contrib.auth logger, preventing potential information leakage through error responses.

Django 1.11.23, 2.1.11 and 2.2.4 include a fix for CVE-2019-14232: If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which were thus vulnerable.

Django 1.11.27, 2.2.9 and 3.0.1 include a fix for CVE-2019-19844: Account takeover. A suitably crafted email address (that is equal to an existing user's email address after case transformation of Unicode characters) would allow an attacker to be sent a password reset token for the matched user account. One mitigation in the new releases is to send password reset tokens only to the registered user email address.

Django has a potential denial-of-service vulnerability in django.utils.html.urlize() and AdminURLFieldWidget. The urlize and urlizetrunc functions, along with AdminURLFieldWidget, are vulnerable to denial-of-service attacks when handling inputs with a very large number of Unicode characters.

Django 2.2.18, 3.0.12 and 3.1.6 include a fix for CVE-2021-3281: The django.utils.archive.extract method (used by "startapp --template" and "startproject --template") allows directory traversal via an archive with absolute paths or relative paths with dot segments.

Affected versions of Django are potentially vulnerable to denial-of-service via the get_supported_language_variant() method. This method was susceptible to a denial-of-service attack when used with very long strings containing specific characters. Exploiting this vulnerability could cause significant delays or crashes in the affected application, potentially leading to service disruption.

An issue was discovered in Django 1.11 before 1.11.22, 2.1 before 2.1.10, and 2.2 before 2.2.3. An HTTP request is not redirected to HTTPS when the SECURE_PROXY_SSL_HEADER and SECURE_SSL_REDIRECT settings are used, and the proxy connects to Django via HTTPS. In other words, django.http.HttpRequest.scheme has incorrect behavior when a client uses HTTP.

Django versions 2.2.19, 3.0.13 and 3.1.7 include a fix for CVE-2021-23336: Web cache poisoning via 'django.utils.http.limited_parse_qsl()'. Django contains a copy of 'urllib.parse.parse_qsl' which was added to backport some security fixes. A further security fix has been issued recently such that 'parse_qsl(' no longer allows using ';' as a query parameter separator by default.

Django 4.2.7, 4.1.13 and 3.2.23 include a fix for CVE-2023-46695: Potential denial of service vulnerability in UsernameField on Windows.
https://www.djangoproject.com/weblog/2023/nov/01/security-releases

Affected versions of Django are vulnerable to Denial-of-Service via django.utils.text.Truncator. The django.utils.text.Truncator chars() and words() methods (when used with html=True) are subject to a potential DoS (denial of service) attack via certain inputs with very long, potentially malformed HTML text. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html template filters, which are thus also vulnerable. NOTE: this issue exists because of an incomplete fix for CVE-2019-14232.

Django 4.2.1, 4.1.9 and 3.2.19 include a fix for CVE-2023-31047: In Django 3.2 before 3.2.19, 4.x before 4.1.9, and 4.2 before 4.2.1, it was possible to bypass validation when using one form field to upload multiple files. This multiple upload has never been supported by forms.FileField or forms.ImageField (only the last uploaded file was validated). However, Django's "Uploading multiple files" documentation suggested otherwise.
https://www.djangoproject.com/weblog/2023/may/03/security-releases

Affected versions of Django are affected by a username enumeration vulnerability caused by timing differences in the django.contrib.auth.backends.ModelBackend.authenticate() method. This method allowed remote attackers to enumerate users through a timing attack involving login requests for users with unusable passwords. The timing difference in the authentication process exposed whether a username was valid or not, potentially aiding attackers in gaining unauthorized access.

Affected versions of Django are vulnerable to potential regular expression denial-of-service (REDoS). django.utils.text.Truncator.words() method (with html=True) and truncatewords_html template filter were subject to a potential regular expression denial-of-service attack using a suitably crafted string (follow up to CVE-2019-14232 and CVE-2023-43665).

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28347: A SQL injection issue was discovered in QuerySet.explain() in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. This occurs by passing a crafted dictionary (with dictionary expansion) as the **options argument, and placing the injection payload in an option name.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Affected versions of Django are vulnerable to a potential ReDoS (regular expression denial of service) in EmailValidator and URLValidator via a very large number of domain name labels of emails and URLs.

Affected versions of Django are vulnerable to potential denial-of-service in intcomma template filter when used with very long strings.

Django 2.2.16, 3.0.10 and 3.1.1 include a fix for CVE-2020-24583: An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). FILE_UPLOAD_DIRECTORY_PERMISSIONS mode was not applied to intermediate-level directories created in the process of uploading files. It was also not applied to intermediate-level collected static directories when using the collectstatic management command.
#NOTE: This vulnerability affects only users of Python versions above 3.7.
https://www.djangoproject.com/weblog/2020/sep/01/security-releases

Django 2.2.27, 3.2.12 and 4.0.2 include a fix for CVE-2022-23833: Denial-of-service possibility in file uploads.
https://www.djangoproject.com/weblog/2022/feb/01/security-releases

Django 2.2.28, 3.2.13 and 4.0.4 include a fix for CVE-2022-28346: An issue was discovered in Django 2.2 before 2.2.28, 3.2 before 3.2.13, and 4.0 before 4.0.4. QuerySet.annotate(), aggregate(), and extra() methods are subject to SQL injection in column aliases via a crafted dictionary (with dictionary expansion) as the passed **kwargs.
https://www.djangoproject.com/weblog/2022/apr/11/security-releases

Django 3.2.17, 4.0.9 and 4.1.6 includes a fix for CVE-2023-23969: In Django 3.2 before 3.2.17, 4.0 before 4.0.9, and 4.1 before 4.1.6, the parsed values of Accept-Language headers are cached in order to avoid repetitive parsing. This leads to a potential denial-of-service vector via excessive memory usage if the raw value of Accept-Language headers is very large.
https://www.djangoproject.com/weblog/2023/feb/01/security-releases

Affected versions of the `django` package are vulnerable to Download of Code Without Integrity Check due to improper handling of user-supplied input in the HTTP FileResponse class. The vulnerability arises because the Content-Disposition header of a FileResponse can be set using a filename derived from user input without sufficient validation. An attacker can exploit this by crafting a request that causes a file with malicious content to be downloaded, potentially executing arbitrary code on the client system when the file is opened.

CVE-2025-64459: Affected versions of the Django package are vulnerable to SQL Injection due to improper input validation, allowing the internal _connector keyword argument to be accepted from untrusted dictionaries via expansion. The .filter(), .exclude(), and .get() methods on QuerySet, as well as the Q class, resolve **kwargs and will treat a supplied _connector value as the logical connector without constraining it to the expected set (AND/OR), permitting attacker-controlled tokens to influence SQL predicate construction.

CVE-2025-64458: Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to slow Unicode NFKC normalization on Windows being applied to untrusted inputs. The django.contrib.auth.views.LoginView and django.contrib.auth.views.LogoutView, and django.views.i18n.set_language normalize user-controlled strings using Python’s NFKC algorithm, which is unusually slow on Windows for huge Unicode sequences and can be triggered to consume excessive CPU.

Affected versions of the Django package are vulnerable to SQL Injection due to insufficient input sanitization in FilteredRelation column aliases. The FilteredRelation class fails to properly validate or escape column alias names when they are provided through dictionary expansion as keyword arguments to QuerySet.annotate() or QuerySet.alias() methods, allowing malicious SQL code to be injected directly into the generated database queries.

Django fixes potential SQL injection in ``FilteredRelation`` column aliases on PostgreSQL.

Django 1.11.23, 2.1.11, and 2.2.4 include a fix for CVE-2019-14233: Due to the behavior of the underlying HTMLParser, django.utils.html.strip_tags would be extremely slow to evaluate certain inputs containing large sequences of nested incomplete HTML entities.

Django 4.1.7, 4.0.10 and 3.2.18 include a fix for CVE-2023-24580: Potential denial-of-service vulnerability in file uploads.
https://www.djangoproject.com/weblog/2023/feb/14/security-releases

An issue was discovered in Django 2.2 before 2.2.16, 3.0 before 3.0.10, and 3.1 before 3.1.1 (when Python 3.7+ is used). The intermediate-level directories of the filesystem cache had the system's standard umask rather than 0o077.

Affected versions of the Django package are vulnerable to Path Traversal due to improper validation of file paths in the django.contrib.admindocs module. The `TemplateDetailView` view allows staff members to verify the existence of arbitrary files by manipulating the file path. An attacker with staff privileges can exploit this vulnerability to check for the presence of files outside the template root directories, and if the `admindocs` templates are customized to display file contents, they can also access the contents of these files.

Django 1.11.21, 2.1.9 and 2.2.2 include a fix for CVE-2019-12308: The clickable Current URL value displayed by the AdminURLFieldWidget displays the provided value without validating it as a safe URL. Thus, a non validated value stored in the database, or a value provided as a URL query parameter payload, could result in an clickable JavaScript link.

Django addresses a memory exhaustion issue in django.utils.numberformat.floatformat(). When floatformat receives a string representation of a number in scientific notation with a large exponent, it could lead to excessive memory consumption. To prevent this, decimals with more than 200 digits are now returned as-is.

Django 2.2.24, 3.1.12, and 3.2.4 include a fix for CVE-2021-33571: In Django 2.2 before 2.2.24, 3.x before 3.1.12, and 3.2 before 3.2.4, URLValidator, validate_ipv4_address, and validate_ipv46_address do not prohibit leading zero characters in octal literals. This may allow a bypass of access control that is based on IP addresses. (validate_ipv4_address and validate_ipv46_address are unaffected with Python 3.9.5+).
https://www.djangoproject.com/weblog/2021/jun/02/security-releases

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of control characters in column aliases within FilteredRelation. The FilteredRelation class fails to properly sanitize column aliases containing control characters when used with QuerySet methods annotate(), aggregate(), extra(), values(), values_list(), and alias() via dictionary expansion (**kwargs).

Affected versions of the Django package are vulnerable to Denial of Service (DoS) due to inefficient string concatenation when processing duplicate HTTP headers in ASGI mode. The ASGIRequest class combines repeated headers using repeated string concatenation, resulting in super-linear (quadratic) time complexity when processing requests with many duplicate headers.

Affected versions of the Django package are vulnerable to SQL Injection due to improper sanitization of band index parameters in PostGIS raster lookups. The raster lookup functionality in Django's GIS module fails to properly validate or escape untrusted data used as a band index when performing spatial queries against PostGIS databases.

Affected versions of the Django package are vulnerable to SQL Injection due to improper handling of column aliases containing periods in QuerySet.order_by() when combined with FilteredRelation. The QuerySet.order_by() method fails to properly sanitize column aliases that contain periods when the same alias is used in FilteredRelation via dictionary expansion. 
https://github.com/django/django/commit/90f5b10784ba5bf369caed87640e2b4394ea3314

A potential denial-of-service vulnerability has been identified in Django's urlize() and urlizetrunc() functions in django.utils.html. This vulnerability can be triggered by inputting huge strings containing a specific sequence of characters.

Django 3.2.14 and 4.0.6 include a fix for CVE-2022-34265: Potential SQL injection via Trunc(kind) and Extract(lookup_name) arguments.
https://www.djangoproject.com/weblog/2022/jul/04/security-releases

Django 2.2.21, 3.1.9 and 3.2.1 include a fix for CVE-2021-31542: MultiPartParser, UploadedFile, and FieldFile allowed directory traversal via uploaded files with suitably crafted file names.
https://www.djangoproject.com/weblog/2021/may/04/security-releases

An issue was discovered in Django 4.2 before 4.2.21, 5.1 before 5.1.9, and 5.2 before 5.2.1. The django.utils.html.strip_tags() function is vulnerable to a potential denial-of-service (slow performance) when processing inputs containing large sequences of incomplete HTML tags. The template filter striptags is also vulnerable, because it is built on top of strip_tags().

In Django 3.2 before 3.2.16, 4.0 before 4.0.8, and 4.1 before 4.1.2, internationalized URLs were subject to a potential denial of service attack via the locale parameter, which is treated as a regular expression.