When BIG-IP PEM iRules are configured on a virtual server (iRules using commands starting with CLASSIFICATION::, CLASSIFY::, PEM::, PSC::, and the urlcatquery command), undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
F5 BIG-IP unknown
Version Status Constraints
21.1.0 unaffected < *
21.0.0 affected < 21.0.0.1
17.5.0 affected < 17.5.1.4
17.1.0 affected < 17.1.3.1
16.1.0 affected < *

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors Products
F5 Subscribe
Big-ip Subscribe

Project Subscriptions

Vendors Products
F5 Subscribe
Big-ip Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://my.f5.com/manage/s/article/K000160875 cve-icon cve-icon
History

Wed, 13 May 2026 18:15:00 +0000

Type Values Removed Values Added
First Time appeared F5
F5 big-ip
Vendors & Products F5
F5 big-ip

Wed, 13 May 2026 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 13 May 2026 15:15:00 +0000

Type Values Removed Values Added
Description When BIG-IP PEM iRules are configured on a virtual server (iRules using commands starting with CLASSIFICATION::, CLASSIFY::, PEM::, PSC::, and the urlcatquery command), undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Title BIG-IP PEM iRules vulnerability
Weaknesses CWE-416
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: f5

Published:

Updated: 2026-05-13T16:14:52.215Z

Reserved: 2026-04-30T23:02:47.670Z

Link: CVE-2026-41218

cve-icon Vulnrichment

Updated: 2026-05-13T16:14:46.553Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-13T16:16:44.473

Modified: 2026-05-13T16:27:11.127

Link: CVE-2026-41218

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-13T18:00:05Z

Weaknesses