CVE-2026-55798

Name	CVE-2026-55798
Description	Pillow is a Python imaging library. Prior to 12.3.0, WindowsViewer.get_command() constructed a cmd.exe shell command by directly embedding a file path into an f-string without escaping and passed the result to subprocess.Popen(..., shell=True), allowing shell metacharacters in the file path to inject arbitrary cmd.exe commands. This issue is fixed in version 12.3.0.
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	11.1.0-5+deb13u2	fixed
	trixie (security)	11.1.0-5+deb13u3	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	Urgency	Origin	Debian Bugs
pillow	source	(unstable)	(not affected)

- pillow <not-affected> (Only affects Windows specific WindowsViewer)
https://github.com/python-pillow/Pillow/security/advisories/GHSA-4x4j-2g7c-83w6