CVE-2026-46420
5.6 · MEDIUMOverview
CVE-2026-46420 is a medium-severity vulnerability affecting shivammathur setup_php. It was published on July 17, 2026 and has a CVSS 3.1 base score of 5.6 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 5.6, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from shivammathur. Update setup_php to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| shivammathur | setup_php | >= 2.25.0, < 2.37.1 | Affected |
Frequently Asked Questions
What is CVE-2026-46420?
CVE-2026-46420 is a medium-severity vulnerability affecting shivammathur setup_php. It was published on July 17, 2026 and has a CVSS 3.1 base score of 5.6 (MEDIUM).
How severe is CVE-2026-46420?
This vulnerability has a CVSS 3.1 base score of 5.6, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-46420?
Check the references section for vendor advisories and patches from shivammathur. Update setup_php to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-46420?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-46420 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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