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.

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 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 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.

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.

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 4.1.7, 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

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 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

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

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

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

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 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.

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 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.

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.

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.

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 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.

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.

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.

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/

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 2.2.26, 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.

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.

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 2.2.18, 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 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.

Django 1.11.19, 2.0.11 and 2.1.6 include a fix for CVE-2019-6975: Uncontrolled Memory Consumption via a malicious attacker-supplied value to the django.utils.numberformat.format() function.

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 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.middleware.common.CommonMiddleware in Django 1.11.x before 1.11.15 and 2.0.x before 2.0.8 has an Open Redirect. A remote user can redirect the target user's browser to an arbitrary site.

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.

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().

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.

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 1.11.16, 2.0.9 and 2.1.1 include a fix for a Race Condition vulnerability that could lead to data loss.
https://github.com/django/django/commit/221ef69a9b89262456bb7abe0e5a4b2fda4a0695

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 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 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 4.2.1, 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

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

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.

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

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

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

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

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.

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

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.

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 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 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.

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.

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 4.1.7, 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

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 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

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

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

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

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 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.

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 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.

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.

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.

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 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.

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.

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.

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/

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 2.2.26, 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.

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.

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 2.2.18, 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 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.

Django 1.11.19, 2.0.11 and 2.1.6 include a fix for CVE-2019-6975: Uncontrolled Memory Consumption via a malicious attacker-supplied value to the django.utils.numberformat.format() function.

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 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.middleware.common.CommonMiddleware in Django 1.11.x before 1.11.15 and 2.0.x before 2.0.8 has an Open Redirect. A remote user can redirect the target user's browser to an arbitrary site.

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.

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().

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.

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 1.11.16, 2.0.9 and 2.1.1 include a fix for a Race Condition vulnerability that could lead to data loss.
https://github.com/django/django/commit/221ef69a9b89262456bb7abe0e5a4b2fda4a0695

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 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 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 4.2.1, 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

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

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.

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

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

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

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

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.

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

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.

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 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 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.

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.

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 4.1.7, 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

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 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

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

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

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

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 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.

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 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.

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.

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.

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 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.

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.

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.

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/

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 2.2.26, 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.

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.

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 2.2.18, 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 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.

Django 1.11.19, 2.0.11 and 2.1.6 include a fix for CVE-2019-6975: Uncontrolled Memory Consumption via a malicious attacker-supplied value to the django.utils.numberformat.format() function.

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 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.middleware.common.CommonMiddleware in Django 1.11.x before 1.11.15 and 2.0.x before 2.0.8 has an Open Redirect. A remote user can redirect the target user's browser to an arbitrary site.

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.

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().

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.

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 1.11.16, 2.0.9 and 2.1.1 include a fix for a Race Condition vulnerability that could lead to data loss.
https://github.com/django/django/commit/221ef69a9b89262456bb7abe0e5a4b2fda4a0695

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 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 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 4.2.1, 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

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

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.

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

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

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

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

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.

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

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.

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 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 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.

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.

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 4.1.7, 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

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 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

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

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

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

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 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.

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 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.

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.

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.

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 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.

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.

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.

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/

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 2.2.26, 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.

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.

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 2.2.18, 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 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.

Django 1.11.19, 2.0.11 and 2.1.6 include a fix for CVE-2019-6975: Uncontrolled Memory Consumption via a malicious attacker-supplied value to the django.utils.numberformat.format() function.

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 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.middleware.common.CommonMiddleware in Django 1.11.x before 1.11.15 and 2.0.x before 2.0.8 has an Open Redirect. A remote user can redirect the target user's browser to an arbitrary site.

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.

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().

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.

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 1.11.16, 2.0.9 and 2.1.1 include a fix for a Race Condition vulnerability that could lead to data loss.
https://github.com/django/django/commit/221ef69a9b89262456bb7abe0e5a4b2fda4a0695

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 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 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 4.2.1, 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

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

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.

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

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

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

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

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.

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

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.

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 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 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.

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.

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 4.1.7, 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

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 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

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

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

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

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 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.

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 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.

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.

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.

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 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.

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.

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.

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/

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 2.2.26, 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.

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.

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 2.2.18, 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 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.

Django 1.11.19, 2.0.11 and 2.1.6 include a fix for CVE-2019-6975: Uncontrolled Memory Consumption via a malicious attacker-supplied value to the django.utils.numberformat.format() function.

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 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.middleware.common.CommonMiddleware in Django 1.11.x before 1.11.15 and 2.0.x before 2.0.8 has an Open Redirect. A remote user can redirect the target user's browser to an arbitrary site.

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.

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().

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.

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 1.11.16, 2.0.9 and 2.1.1 include a fix for a Race Condition vulnerability that could lead to data loss.
https://github.com/django/django/commit/221ef69a9b89262456bb7abe0e5a4b2fda4a0695

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 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 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 4.2.1, 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

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

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.

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

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

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

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

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.

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