CVE-2026-96636

Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator can decode that frame and commit hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.

Score

CVSS 3.1 6.5 Medium

Status

Analyzed - security-advisories@github.com

Published

2026-10-21

Last modified

2026-10-27

Weaknesses

CWE-400, CWE-409

Affected products

• Pillow (Python)
• Pillow (Python-pillow)

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-p8hx-v2p6-rp84
• https://github.com/python-pillow/Pillow/pull/10011
• https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48
• https://github.com/python-pillow/Pillow/releases/tag/13.0.0