Detections
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CVE-2026-109618

critical

Description

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).

References

https://php2shell.delftintellab.com

https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w

https://cert-portal.siemens.com/productcert/html/ssa-566435.html

http://www.openwall.com/lists/oss-security/2026/10/23/5

http://www.openwall.com/lists/oss-security/2026/10/21/6

https://hackread.com/insignary-releases-free-insignary-chk-tool-to-detect-php2shell-and-node2shell-exposure/

https://www.bleepingcomputer.com/news/security/cisa-warns-of-fragnesia-linux-flaw-chained-in-php2shell-attacks/

https://www.securityweek.com/china-linked-hackers-exploit-php2shell-to-root-firewalls/

https://thehackernews.com/2026/10/php2shell-attack-roots-25-servers.html

https://thehackernews.com/2026/10/attackers-exploit-php2shell-flaws-in.html

https://www.cisa.gov/news-events/alerts/2026/10/26/cisa-adds-two-known-exploited-vulnerabilities-catalog

https://www.bleepingcomputer.com/news/security/php2shell-security-flaws-now-sucessfully-exploited-in-the-wild/

https://www.securityweek.com/php2shell-patches-land-as-first-exploitation-attempts-hit-sensors/

https://aws.amazon.com/blogs/security/amazon-threat-intelligence-identifies-php2shell-exploitation-prior-to-public-disclosure-in-madpot/

https://kb.cert.org/vuls/id/763488

https://www.wsj.com/tech/cybersecurity/ai-just-found-a-bug-that-puts-up-to-70-of-the-worlds-websites-at-risk-fd0902ea

https://www.paloaltonetworks.com/blog/2026/10/millions-of-php-instances-exposed-what-organizations-need-to-do-right-now/

https://www.cisa.gov/news-events/alerts/2026/10/21/critical-vulnerabilities-php-require-immediate-patching

https://unit42.paloaltonetworks.com/cve-2026-109618-cve-2026-109619/

https://krebsonsecurity.com/2026/10/widespread-php-flaw-may-cause-many-site-outages-today/

https://www.bleepingcomputer.com/news/security/php-warns-admins-of-two-critical-flaws-emergency-patches-coming-tomorrow/

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-109618

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-107260

http://seclists.org/fulldisclosure/2026/Oct/51

Details

Source: Mitre, NVD

Published: 2026-10-21

Updated: 2026-11-05

Named Vulnerability: php2shellNamed Vulnerability: PHP2shellNamed Vulnerability: PHP2ShellKnown Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 10

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Severity: Critical

CVSS v3

Base Score: 9.8

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

Severity: Critical

CVSS v4

Base Score: 9.2

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

Severity: Critical

EPSS

EPSS: 0.99999

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Concern