CVE-2026-40261 - Vulnerability Analysis

Overview

Composer 1.0 through 2.2.26 and 2.3 through 2.9.5 contain a command injection caused by improper escaping of user-supplied parameters in Perforce::syncCodeBase() and Perforce::generateP4Command() methods, letting attackers inject arbitrary commands during dependency installation or update from source, exploit requires malicious package metadata from compromised or malicious Composer repositories.

Severity & Score

Impact

Attackers can execute arbitrary commands on the system during dependency installation or update, potentially leading to full system compromise.

Mitigation

Upgrade to Composer 2.2.27 or 2.9.6 or later versions; alternatively, avoid installing dependencies from source by using --prefer-dist or preferred-install: dist and use only trusted repositories.

References

• https://github.com/composer/composer/releases/tag/2.9.6
• https://github.com/composer/composer/security/advisories/GHSA-gqw4-4w2p-838q

Related Resources

• Vulnerability Intelligence Dashboard
• Credential Scanner