CVE-2026-40176

Name	CVE-2026-40176
Description	Composer is a dependency manager for PHP. Versions 1.0 through 2.2.26 and 2.3 through 2.9.5 contain a command injection vulnerability in the Perforce::generateP4Command() method, which constructs shell commands by interpolating user-supplied Perforce connection parameters (port, user, client) without proper escaping. An attacker can inject arbitrary commands through these values in a malicious composer.json declaring a Perforce VCS repository, leading to command execution in the context of the user running Composer, even if Perforce is not installed. VCS repositories are only loaded from the root composer.json or the composer config directory, so this cannot be exploited through composer.json files of packages installed as dependencies. Users are at risk if they run Composer commands on untrusted projects with attacker-supplied composer.json files. This issue has been fixed in Composer 2.2.27 (2.2 LTS) and 2.9.6 (mainline).
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
composer (PTS)	bullseye (security), bullseye	2.0.9-2+deb11u4	vulnerable
	bookworm	2.5.5-1+deb12u3	vulnerable
	bookworm (security)	2.5.5-1+deb12u2	vulnerable
	trixie	2.8.8-1+deb13u1	vulnerable
	forky, sid	2.9.7-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
composer	source	(unstable)	2.9.7-1

Notes

[trixie] - composer <no-dsa> (Minor issue; can be fixed via point release)
[bookworm] - composer <no-dsa> (Minor issue; can be fixed via point release)
https://github.com/composer/composer/security/advisories/GHSA-wg36-wvj6-r67p