CVE-2026-96642

Name	CVE-2026-96642
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.
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-3j72-p6qg-6xp7
https://github.com/python-pillow/Pillow/pull/10012
Fixed by: https://github.com/python-pillow/Pillow/commit/19b695fdcc5eddc37374e2b1645fc4185edaf71d (13.0.0)