Vulnerability Description
Pillow is a Python imaging library. Prior to 13.0.0, the TarIO initializer in src/PIL/TarIO.py accepts a negative octal member size and computes a backward seek that returns to the same 512-byte header. When the requested member name does not match, the parser repeatedly reads that header, consumes a full CPU core, and never returns. TarIO is reached only when an application directly uses PIL.TarIO.TarIO rather than the default Image.open() path. This issue is fixed in version 13.0.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Python | Pillow | < 13.0.0 |
Related Weaknesses (CWE)
References
- https://github.com/python-pillow/Pillow/commit/19b695fdcc5eddc37374e2b1645fc4185Patch
- https://github.com/python-pillow/Pillow/pull/10012Issue Tracking
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0Release Notes
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-3j72-p6qg-6xp7Vendor Advisory
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-3j72-p6qg-6xp7Vendor Advisory
FAQ
What is CVE-2026-96642?
CVE-2026-96642 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Pillow is a Python imaging library. Prior to 13.0.0, the TarIO initializer in src/PIL/TarIO.py accepts a negative octal member size and computes a backward seek that returns to the same 512-byte heade...
How severe is CVE-2026-96642?
CVE-2026-96642 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-96642?
Check the references section above for vendor advisories and patch information. Affected products include: Python Pillow.