CVE-2026-96639

Name	CVE-2026-96639
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
pillow (PTS)	bookworm, bookworm (security)	9.4.0-1.1+deb12u1	vulnerable
	trixie	11.1.0-5+deb13u4	vulnerable
	trixie (security)	11.1.0-5+deb13u3	vulnerable
	forky	12.3.0-1	vulnerable
	sid	13.0.0-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
pillow	source	(unstable)	13.0.0-1

Notes

https://github.com/python-pillow/Pillow/security/advisories/GHSA-v9pv-5gc8-w2m6
https://github.com/python-pillow/Pillow/pull/10105
Fixed by: https://github.com/python-pillow/Pillow/commit/78d97d994579aef81aafe123773d525f40f2522a (13.0.0)