Vulnerability Description
Jinja is an extensible templating engine. Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template to execute arbitrary Python code. To exploit the vulnerability, an attacker needs to control the content of a template. Whether that is the case depends on the type of application using Jinja. This vulnerability impacts users of applications which execute untrusted templates. Jinja's sandbox does catch calls to str.format and ensures they don't escape the sandbox. However, it's possible to use the |attr filter to get a reference to a string's plain format method, bypassing the sandbox. After the fix, the |attr filter no longer bypasses the environment's attribute lookup. This vulnerability is fixed in 3.1.6.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Palletsprojects | Jinja | < 3.1.6 |
| Debian | Debian Linux | 11.0 |
Related Weaknesses (CWE)
References
- https://github.com/pallets/jinja/commit/90457bbf33b8662926ae65cdde4c4c32e756e403Patch
- https://github.com/pallets/jinja/security/advisories/GHSA-cpwx-vrp4-4pq7Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2025/04/msg00022.html
- https://lists.debian.org/debian-lts-announce/2025/04/msg00045.htmlMailing ListThird Party Advisory
FAQ
What is CVE-2025-27516?
CVE-2025-27516 is a vulnerability with a CVSS score of 8.8 (HIGH). Jinja is an extensible templating engine. Prior to 3.1.6, an oversight in how the Jinja sandboxed environment interacts with the |attr filter allows an attacker that controls the content of a template...
How severe is CVE-2025-27516?
CVE-2025-27516 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-27516?
Check the references section above for vendor advisories and patch information. Affected products include: Palletsprojects Jinja, Debian Debian Linux.