CVE-2026-42309

Name	CVE-2026-42309
Description	Pillow is a Python imaging library. From version 11.2.1 to before version 12.2.0, passing nested lists as coordinates to APIs that accept coordinates such as ImagePath.Path, ImageDraw.ImageDraw.polygon and ImageDraw.ImageDraw.line could cause a heap buffer overflow, as nested lists were recursively unpacked beyond the allocated buffer. Coordinate lists are now validated to contain exactly two numeric coordinates. This issue has been patched in version 12.2.0.
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)	bullseye	8.1.2+dfsg-0.3+deb11u2	fixed
	bullseye (security)	8.1.2+dfsg-0.3+deb11u3	fixed
	bookworm, bookworm (security)	9.4.0-1.1+deb12u1	fixed
	trixie (security), trixie	11.1.0-5+deb13u2	fixed
	forky, sid	12.2.0-1	fixed

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

Package	Type	Release	Fixed Version
pillow	source	bullseye	(not affected)
pillow	source	bookworm	(not affected)
pillow	source	trixie	(not affected)
pillow	source	(unstable)	12.2.0-1

Notes

[trixie] - pillow <not-affected> (Vulnerable code introduced later)
[bookworm] - pillow <not-affected> (Vulnerable code introduced later)
[bullseye] - pillow <not-affected> (Vulnerable code introduced later)
https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xmw-vc9v-4wf2