CVE-2026-109618: PHP Group PHP (Critical, CVSS 9.2)
- CVSS
- 9.2 Critical (v4.0)
- EPSS
- 5.3% chance of exploitation in the next 30 days (higher than 92.5% of CVEs)
- Exploited in the wild
- Not on CISA’s KEV list
- Public exploit
- Yes, reported in Exploit-DB, a Nuclei template and 485 GitHub repositories
- Weakness
- CWE-1325, CWE-416, CWE-755, CWE-824
- Vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N- Published
- Oct 21, 2026
What it is
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).
Description from the National Vulnerability Database.
What to do
Check whether you run PHP Group PHP, then apply the vendor’s fix or mitigation from the advisories below. Because this flaw is exploited or has public exploit code, treat it as urgent and check for signs of compromise, not just the patch level.
Advisories and fixes
ThreatRoundup coverage
PHP2Shell Was Being Exploited Four Days Before Anyone Knew
Leaked ‘php2shell’ Bugs Force PHP Into an Emergency Patch Day
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.