CVE-2026-109618
PHP Group PHP, Siemens RUGGEDCOM APE1808
Published 21 Oct 2026 · updated 28 Oct 2026 · Analyzed
Exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on 26 Oct 2026, with a remediation deadline of 29 Oct 2026 for US federal agencies.
Required action: Apply 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.
Description
PHP uses longjmp() for out-of-memory (OOM) errors to exit the current context and abort handling of the request. Some contexts may not properly account for this scenario and leave request memory in an uninitialized state before performing an allocation. The subsequent request cleanup procedure may read or branch on this memory. Multiple OOM strategies can consistently trigger this condition and lead to remote code execution (RCE).
References
- github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w · Mitigation, Vendor Advisory
- www.openwall.com/lists/oss-security/2026/10/21/6 · Mailing List, Third Party Advisory
- www.openwall.com/lists/oss-security/2026/10/23/5 · Mailing List, Third Party Advisory
- arcticwolf.com/resources/blog/php2shell-critical-php-vulnerabilities-enable-unauthenticated-remote-code-execution/ · Third Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-566512.html · Third Party Advisory
- php2shell.delftintellab.com/ · Third Party Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-109618 · US Government Resource
- www.wiz.io/blog/php2shell-php-rce · Third Party Advisory