Vulnerability Description
setup-php is a GitHub action to set up PHP with extensions, php.ini configuration, coverage drivers, and tools. From 2.25.0 prior to 2.37.1, shivammathur/setup-php resolves the PHP version from repository-controlled files such as .php-version, composer.lock through platform-overrides.php, and composer.json through config.platform.php, and insufficiently constrains those values before incorporating them into generated shell or PowerShell setup scripts, allowing command injection on a GitHub Actions runner when workflows such as pull_request_target check out attacker-controlled contents before invoking setup-php. This issue is fixed in version 2.37.1.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Shivammathur | Setup Php | >= 2.25.0, < 2.37.1 |
Related Weaknesses (CWE)
References
- https://github.com/shivammathur/setup-php/commit/eeef37e059fb5368a5bc8ed8ce45ff5Patch
- https://github.com/shivammathur/setup-php/releases/tag/2.37.1ProductRelease Notes
- https://github.com/shivammathur/setup-php/security/advisories/GHSA-pqwm-q9pv-ph8PatchVendor Advisory
FAQ
What is CVE-2026-46420?
CVE-2026-46420 is a vulnerability with a CVSS score of 5.6 (MEDIUM). setup-php is a GitHub action to set up PHP with extensions, php.ini configuration, coverage drivers, and tools. From 2.25.0 prior to 2.37.1, shivammathur/setup-php resolves the PHP version from reposi...
How severe is CVE-2026-46420?
CVE-2026-46420 has been rated MEDIUM with a CVSS base score of 5.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-46420?
Check the references section above for vendor advisories and patch information. Affected products include: Shivammathur Setup Php.