CVE-2026-84361: Command Injection

Description

Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30 and 2.10.3, a malicious dependency package from a custom Composer repository or an untrusted composer.lock file could set source.type to perforce and source.url to an rsh: or jsh: P4PORT value. When the Perforce p4 client was installed and Composer installed the package from source through composer install or composer update, including --prefer-source, Composer\Util\Perforce passed the address to p4 without validation, causing p4 to run a local command with the privileges of the user or CI account. Packagist.org does not permit Perforce source metadata. This issue is fixed in versions 2.2.30 and 2.10.3.

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Weakness Type (CWE)

CWE-78 OS Command Injection

References

Other References

https://github.com/composer/composer/commit/0aac50528e83ed635cf788333635897469440220 https://github.com/composer/composer/commit/199ad81a9cc6a2a5164ad79a8da26b2e19e521af https://github.com/composer/composer/releases/tag/2.10.3 https://github.com/composer/composer/releases/tag/2.2.30 https://github.com/composer/composer/security/advisories/GHSA-rvx4-ffvw-m9q3

Frequently Asked Questions

What is CVE-2026-84361? +

Composer is a dependency Manager for the PHP language. From 1.0 until 2.2.30 and 2.10.3, a malicious dependency package from a custom Composer repository or an untrusted composer.lock file could set source.type to perforce and source.url to an rsh: or jsh: P4PORT value. When the Perforce p4 client was installed and Composer installed the package from source through composer install or composer update, including --prefer-source, Composer\Util\Perforce passed the address to p4 without validation, causing p4 to run a local command with the privileges of the user or CI account. Packagist.org does not permit Perforce source metadata. This issue is fixed in versions 2.2.30 and 2.10.3.

How do I check if I'm vulnerable to CVE-2026-84361? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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