Summary
PHP contains an out-of-memory corruption vulnerability that allows for unauthenticated remote code execution.
Remediation
CISA required actionApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
References
- Advisoryhttps://www.php.net/
- Advisoryhttps://www.cisa.gov/news-events/alerts/2026/10/21/critical-vulnerabilities-php-require-immediate-patching
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- Advisoryhttps://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- Advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-109618
- Advisoryhttps://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w
- Advisoryhttps://www.wiz.io/blog/php2shell-php-rce
- Advisoryhttps://arcticwolf.com/resources/blog/php2shell-critical-php-vulnerabilities-enable-unauthenticated-remote-code-execution/
- Advisoryhttps://php2shell.delftintellab.com
- Advisoryhttps://cert-portal.siemens.com/productcert/html/ssa-566512.html
- Advisoryhttps://cert-portal.siemens.com/productcert/html/ssa-566435.html
- Advisoryhttps://cert-portal.siemens.com/productcert/html/ssa-166980.html