What’s Vulnerable › Vulnerabilities

CVE-2026-46420: setup-php: Command Injection in Repository-Derived PHP Version Resolution

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-17 · updated 2026-10-24
• Weakness: CWE-78

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.

Affected products

• shivammathur setup-php: from 2.25.0 before 2.37.1 — fixed in 2.37.1

How to fix

Upgrade to a fixed version: shivammathur setup-php 2.37.1. Check the vendor advisory for mitigations.

References

• https://github.com/shivammathur/setup-php/commit/eeef37e059fb5368a5bc8ed8ce45ff54bd39b80b
• https://github.com/shivammathur/setup-php/releases/tag/2.37.1
• https://github.com/shivammathur/setup-php/security/advisories/GHSA-pqwm-q9pv-ph8r

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