Critical Security Update for python-jinja2: Jinja Sandbox Breakout Vulnerability
Summary
ALSA-2025:3388: Important: python-jinja2 security update. Affects python3-jinja2 versions < 2.10.1-7.el8_10. Fixed in 2.10.1-7.el8_10. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
python-jinja2 is a popular templating engine for Python, widely used for rendering dynamic web pages. It allows developers to create templates that can be rendered with data, providing a powerful way to separate application logic from presentation. However, vulnerabilities in this package can lead to serious security risks, such as unauthorized access to system resources.
Vulnerability Detail
The vulnerability identified as CVE-2025-27516 allows for a sandbox breakout through the attr filter selecting the format method. This means that an attacker could potentially exploit this flaw to execute arbitrary code or access sensitive data outside the intended sandbox environment. The implications of this vulnerability are significant, as it could lead to unauthorized actions being performed on the server, compromising the integrity and confidentiality of the application.
How To Fix
Minimum fixed version
2.10.1-7.el8_10
This is the first release that contains the fix.
sudo dnf update python3-jinja2Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If immediate updating is not feasible, consider implementing strict input validation and sanitization in your application to mitigate the risk of exploitation until the package can be updated.
Conclusion
The python-jinja2 package has a critical vulnerability that requires immediate attention. By updating to the latest patched version, you can protect your application from potential exploits. Additionally, utilizing tools like Vulert can help you monitor and manage vulnerabilities effectively.
See every vulnerability recorded for python3-jinja2 →
FAQ
CVE-2025-27516 is a security vulnerability in python-jinja2 that allows for a sandbox breakout, potentially enabling attackers to execute arbitrary code.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
The risks include unauthorized access to system resources, data breaches, and the potential for attackers to execute malicious code on the server.
Yes, the patched version of python3-jinja2 is 2.10.1-7.el8_10. Updating to this version will resolve the vulnerability.
Implement strict input validation and sanitization in your application as a temporary measure to reduce the risk of exploitation.
Related vulnerabilities
Recent vulnerabilities recorded for python3-jinja2.
