PHP Memory Corruption Vulnerability
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 le
What happened
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).
CISA lists it as exploited, added 26 Oct 2026.
Does it affect you
Names Palo Alto Networks PAN-OS. Enter the product and version you run to place it against the affected range the vendor published.
What to do
- Follow the vendor advisory for the fixed release and any interim mitigation.
github.com - 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.
cisa.gov
CISA’s notes for this entry:
- This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: php.net/
- cisa.gov/news-events/alerts/2026/10/21/critical-vulnerabilities-php-require-immediate-patching
- BOD 26-04: cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- Forensics Triage Requirements: cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- nvd.nist.gov/vuln/detail/CVE-2026-109618
Affected, as published to NVD
- panos
- Palo Alto Networks PAN-OS: exactly 12.2.4
The record
- NVD status
- Analyzed
- Published
- 21 Oct 2026, last modified 26 Oct 2026 (NVD)
- Severity
- CVSS 3.1 base score 9.8, Critical — computed here from the vector; NVD states 9.8.
- Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness
- CWE-416 Use After Free, CWE-755 Improper Handling of Exceptional Conditions, CWE-824 Access of Uninitialized Pointer, CWE-1325 (NVD; names by MITRE)
- Exploitation
- Listed in CISA’s Known Exploited Vulnerabilities catalogue since 26 Oct 2026; federal remediation due 29 Oct 2026. CISA entry
- Exploit probability
- EPSS 100.0%, 100th percentile — FIRST, scored 26 Oct 2026. FIRST EPSS
- Vendor
- PHP Group · PHP (CISA)
References on the NVD record
- github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79wMitigationVendor Advisory
- openwall.com/lists/oss-security/2026/10/21/6Mailing ListThird Party Advisory
- openwall.com/lists/oss-security/2026/10/23/5Mailing ListThird Party Advisory
- cert-portal.siemens.com/productcert/html/ssa-566512.htmlThird Party Advisory
- wiz.io/blog/php2shell-php-rceThird Party Advisory
Reporting that names this identifier
- CISA Adds Two Known Exploited Vulnerabilities to Catalog — CISA, 22 hr ago
- PHP2Shell security flaws now sucessfully exploited in the wild — BleepingComputer, 1 d ago
- PHP2Shell Exploitation Hits Government Entity Amid Global Scanning and Signs of AI-Assisted Hacking — The Hacker News, 2 d ago
- PHP2Shell Exploit Attempts Hit Millions as Attackers Try to Deploy Mirai Malware — The Hacker News, 4 d ago
- New PHP2Shell scanner checks your hosts for CVE-2026-109618 and CVE-2026-109619 — Help Net Security, 5 d ago
- PHP ships emergency patches for critical PHP2Shell flaws — BleepingComputer, 6 d ago
- PHP2Shell: Critical PHP vulnerabilities patched, update now! — Help Net Security, 6 d ago
- Critical Vulnerabilities in PHP Require Immediate Patching — CISA, 6 d ago
Sources
The verdict above is computed from the products and versions you entered and the affected ranges the vendor published to NVD. It does not inspect your environment, and this site never reports a product as unaffected: why.