by Kastro
Paper/Archive/CVE-2026-46420

CVE-2026-46420

shivammathur setup-php — setup-php: Command Injection in Repository-Derived PHP Version Resolution

EPSS 2%CVSS 9.8
critical.is priorityof 100
46
CVSS 9.8 (NVD)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 80.8.808 × 2016.2No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
setup-php>= 2.25.0, < 2.37.1–CNA

Scores by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
GitHub_M (CNA)5.6CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: partial

References

refgithub.com/shivammathur/setup-php/security/advisories/GHSA-pqwm-q9pv-ph8rrefgithub.com/shivammathur/setup-php/commit/eeef37e059fb5368a5bc8ed8ce45ff54bd39b80brefgithub.com/shivammathur/setup-php/releases/tag/2.37.1