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.
What this means for your business
- FIRST's prediction model gives it a 0.5% chance of attack attempts being seen in the next 30 days, ranking above 43% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- Not yet scored
- CVSS v4
- 7.7
- Weakness
- CWE-78
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-09-01
- Last modified
- 2026-09-09
- Sources
- NVD
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