Patchfirst
CVE-2026-109618 KEVPublic exploit Critical · 9.8 EPSS >99.9%

PHP Memory Corruption Vulnerability

PHP Group · PHP

Summary

A memory corruption flaw in PHP's request handling lets out-of-memory conditions, which are handled via longjmp(), leave request memory uninitialized before a later allocation, and the cleanup routine then reads or branches on that memory. An unauthenticated remote attacker with network access can trigger this without user interaction by using one of several out-of-memory strategies that consistently reproduce the condition, potentially achieving remote code execution.

Official description · NVD

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).

Breakdown
79.9 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
2/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

First seen exploited the day it was disclosed. Public exploit code (PoC-in-GitHub) was available 3 days before disclosure.

  1. Public exploit codePoC-in-GitHub3 days before
  2. DisclosedFirst seen exploitedVulnCheck KEV evidenceday 0
  3. Added to CISA KEVEU database agrees+5 days

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

2 , grouped by in kill-chain order, 2 cited passages 2

Initial AccessTA0001

Exploit Public-Facing Application T1190 Medium
AI mapping from the description · how it is exploited

network-reachable PHP request triggers memory corruption

lead to remote code execution (RCE)
From the official description (NVD) Original (opens in a new tab) ↗

ExecutionTA0002

Command and Scripting Interpreter T1059 Medium
AI mapping from the description · primary impact

RCE yields arbitrary command execution in the process

lead to remote code execution (RCE)
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 244 general rules for its techniques

Rules for this CVE

0 that reference CVE-2026-109618 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

Sigma rules © SigmaHQ, Detection Rule License 1.1; linked, not reproduced.

What security researchers reported

Not named in any threat report yet

Also mentioned in 50 community threat pulses (AlienVault OTX)

Weaker evidence

Pulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.

References

11 links, grouped by NVD tag
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