In Jinja2, the from_string function is prone to Server Side Template Injection (SSTI) where it takes the "source" parameter as a template object, renders it, and then returns it. The attacker can exploit it with {{INJECTION COMMANDS}} in a URI. 
NOTE: The maintainer and multiple third parties believe that this vulnerability isn't valid because users shouldn't use untrusted templates without sandboxing.

Jinja2 before 3.1.3 is affected by a Cross-Site Scripting vulnerability. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template. The Jinja 'xmlattr' filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

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

Jinja2 2.10.1 adds 'SandboxedEnvironment' to handle 'str.format_map' in order to prevent code execution through untrusted format strings.
https://github.com/pallets/jinja/commit/a2a6c930bcca591a25d2b316fcfd2d6793897b26

In Jinja2, the from_string function is prone to Server Side Template Injection (SSTI) where it takes the "source" parameter as a template object, renders it, and then returns it. The attacker can exploit it with {{INJECTION COMMANDS}} in a URI. 
NOTE: The maintainer and multiple third parties believe that this vulnerability isn't valid because users shouldn't use untrusted templates without sandboxing.

Jinja2 before 3.1.3 is affected by a Cross-Site Scripting vulnerability. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template. The Jinja 'xmlattr' filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

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

Jinja2 2.10.1 adds 'SandboxedEnvironment' to handle 'str.format_map' in order to prevent code execution through untrusted format strings.
https://github.com/pallets/jinja/commit/a2a6c930bcca591a25d2b316fcfd2d6793897b26

In Jinja2, the from_string function is prone to Server Side Template Injection (SSTI) where it takes the "source" parameter as a template object, renders it, and then returns it. The attacker can exploit it with {{INJECTION COMMANDS}} in a URI. 
NOTE: The maintainer and multiple third parties believe that this vulnerability isn't valid because users shouldn't use untrusted templates without sandboxing.

Jinja2 before 3.1.3 is affected by a Cross-Site Scripting vulnerability. Special placeholders in the template allow writing code similar to Python syntax. It is possible to inject arbitrary HTML attributes into the rendered HTML template. The Jinja 'xmlattr' filter can be abused to inject arbitrary HTML attribute keys and values, bypassing the auto escaping mechanism and potentially leading to XSS. It may also be possible to bypass attribute validation checks if they are blacklist-based.

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

Jinja2 2.10.1 adds 'SandboxedEnvironment' to handle 'str.format_map' in order to prevent code execution through untrusted format strings.
https://github.com/pallets/jinja/commit/a2a6c930bcca591a25d2b316fcfd2d6793897b26