Vulnerability Description
Pillow is a Python imaging library. From 11.0.0 until 13.0.0, multi-frame loaders can retain an ImagingCore allocation created for a narrow frame mode while a later frame of the same dimensions changes the logical mode and decoder tiles to wider RGB or CMYK data. ImageFile.load_prepare() reuses the stale native storage because _im is non-null without verifying that its mode and size still match. Crafted PSD, MPO, DCX, or MIC frame transitions can then write wider pixels into the narrow allocation, causing native out-of-bounds writes and crashes. The MPO path can also cause a native over-read and, in demonstrated runtime-specific profiles, command execution. This issue is fixed in version 13.0.0.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Python | Pillow | >= 11.0.0, < 13.0.0 |
Related Weaknesses (CWE)
References
- https://github.com/python-pillow/Pillow/commit/78d97d994579aef81aafe123773d525f4Patch
- https://github.com/python-pillow/Pillow/pull/10105Issue Tracking
- https://github.com/python-pillow/Pillow/releases/tag/13.0.0Release Notes
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-v9pv-5gc8-w2m6Vendor Advisory
FAQ
What is CVE-2026-96639?
CVE-2026-96639 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Pillow is a Python imaging library. From 11.0.0 until 13.0.0, multi-frame loaders can retain an ImagingCore allocation created for a narrow frame mode while a later frame of the same dimensions change...
How severe is CVE-2026-96639?
CVE-2026-96639 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-96639?
Check the references section above for vendor advisories and patch information. Affected products include: Python Pillow.