---
title: "CVE-2026-109618: PHP - Remote Code Execution"
description: "PHP contains a remote code execution caused by improper handling of out-of-memory errors using longjmp(), letting remote attackers execute arbitrary code by triggering uninitialized memory usage during request cleanup, exploit requires crafted requests causing OOM."
url: https://panop.io/threat-heartbeat/CVE-2026-109618/
---

# CVE-2026-109618 PHP - Remote Code Execution

PHP contains a remote code execution caused by improper handling of out-of-memory errors using longjmp(), letting remote attackers execute arbitrary code by triggering uninitialized memory usage during request cleanup, exploit requires crafted requests causing OOM.

CVSS base score 9.8 /10

Critical

CISA KEV

Exploited in the wild

Public exploit

Proof of concept available

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-109618)

## Details

Type

Remote Code Execution

Impact

Remote Code Execution

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

21 October 2026

Updated

22 October 2026

Weakness

[CWE-416](https://cwe.mitre.org/data/definitions/416.html)

## Vendor fix

Update to the latest PHP version with out-of-memory handling fixes.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-109618](https://nvd.nist.gov/vuln/detail/CVE-2026-109618)
- [https://previdian.com/CVE-2026-109618](https://previdian.com/CVE-2026-109618)
- [https://watchtowr.com/intelligence/php-remote-code-execution-php2shell/](https://watchtowr.com/intelligence/php-remote-code-execution-php2shell/)
- [https://www.fastly.com/blog/fastlys-proactive-protection-critical-php-rce-cve-2026-109618](https://www.fastly.com/blog/fastlys-proactive-protection-critical-php-rce-cve-2026-109618)
- [https://www.wiz.io/blog/php2shell-php-rce](https://www.wiz.io/blog/php2shell-php-rce)
- [http://www.openwall.com/lists/oss-security/2026/10/21/6](http://www.openwall.com/lists/oss-security/2026/10/21/6)
- [https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w](https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w)
- [https://api.vulncheck.com/v3/index/vulncheck-canaries?cve=CVE-2026-109618&date=2026-10-22](https://api.vulncheck.com/v3/index/vulncheck-canaries?cve=CVE-2026-109618&date=2026-10-22)
- [https://aws.amazon.com/blogs/security/amazon-threat-intelligence-identifies-php2shell-exploitation-prior-to-public-disclosure-in-madpot/](https://aws.amazon.com/blogs/security/amazon-threat-intelligence-identifies-php2shell-exploitation-prior-to-public-disclosure-in-madpot/)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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