CVE-2026-109618
critical CISA KEVPHP Memory Corruption Vulnerability
Vendor / product: PHP Group — PHP
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).
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Required action (CISA)
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.
Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w security@php.net
- http://seclists.org/fulldisclosure/2026/Oct/51 af854a3a-2127-422b-91ae-364da2661108
- http://www.openwall.com/lists/oss-security/2026/10/21/6 af854a3a-2127-422b-91ae-364da2661108
- http://www.openwall.com/lists/oss-security/2026/10/23/5 af854a3a-2127-422b-91ae-364da2661108
- https://arcticwolf.com/resources/blog/php2shell-critical-php-vulnerabilities-enable-unauth... 134c704f-9b21-4f2e-91b3-4a467353bcc0
- https://cert-portal.siemens.com/productcert/html/ssa-166980.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://cert-portal.siemens.com/productcert/html/ssa-566435.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://cert-portal.siemens.com/productcert/html/ssa-566512.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
- https://php2shell.delftintellab.com 134c704f-9b21-4f2e-91b3-4a467353bcc0
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-109618 134c704f-9b21-4f2e-91b3-4a467353bcc0
- https://www.wiz.io/blog/php2shell-php-rce 134c704f-9b21-4f2e-91b3-4a467353bcc0