CVE-2026-41218: BIG-IP PEM iRules vulnerability
Published May 13, 2026
·Updated
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.
Affected Software
85 affected components
F5 Networks BIG-IP PEM
F5 BIG-IP Access Policy Manager>=17.1.0<=17.1.3
F5 BIG-IP Access Policy Manager>=17.5.0<=17.5.1
F5 BIG-IP Advanced Firewall Manager>=17.1.0<=17.1.3
F5 BIG-IP Advanced Firewall Manager>=17.5.0<=17.5.1
F5 Big-ip Advanced Web Application Firewall>=17.1.0<=17.1.3
F5 Big-ip Advanced Web Application Firewall>=17.5.0<=17.5.1
F5 BIG-IP Analytics>=17.1.0<=17.1.3
F5 BIG-IP Analytics>=17.5.0<=17.5.1
F5 Big-ip Application Acceleration Manager>=17.1.0<=17.1.3
F5 Big-ip Application Acceleration Manager>=17.5.0<=17.5.1
F5 BIG-IP Application Security Manager>=17.1.0<=17.1.3
F5 BIG-IP Application Security Manager>=17.5.0<=17.5.1
F5 Big-ip Application Visibility And Reporting>=17.1.0<=17.1.3
F5 Big-ip Application Visibility And Reporting>=17.5.0<=17.5.1
F5 Big-ip Automation Toolchain>=17.1.0<=17.1.3
F5 Big-ip Automation Toolchain>=17.5.0<=17.5.1
F5 Big-ip Carrier-grade Nat>=17.1.0<=17.1.3
F5 Big-ip Carrier-grade Nat>=17.5.0<=17.5.1
F5 BIG-IP Container Ingress Services>=17.1.0<=17.1.3
F5 BIG-IP Container Ingress Services>=17.5.0<=17.5.1
F5 Big-ip Ddos Hybrid Defender>=17.1.0<=17.1.3
F5 Big-ip Ddos Hybrid Defender>=17.5.0<=17.5.1
F5 Big-ip Domain Name System>=17.1.0<=17.1.3
F5 Big-ip Domain Name System>=17.5.0<=17.5.1
F5 BIG-IP Edge Gateway>=17.1.0<=17.1.3
F5 BIG-IP Edge Gateway>=17.5.0<=17.5.1
F5 Big-ip Fraud Protection Service>=17.1.0<=17.1.3
F5 Big-ip Fraud Protection Service>=17.5.0<=17.5.1
F5 Big-ip Global Traffic Manager>=17.1.0<=17.1.3
F5 Big-ip Global Traffic Manager>=17.5.0<=17.5.1
F5 Big-ip Link Controller>=17.1.0<=17.1.3
F5 Big-ip Link Controller>=17.5.0<=17.5.1
F5 Big-ip Local Traffic Manager>=17.1.0<=17.1.3
F5 Big-ip Local Traffic Manager>=17.5.0<=17.5.1
F5 Big-ip Policy Enforcement Manager>=17.1.0<=17.1.3
F5 Big-ip Policy Enforcement Manager>=17.5.0<=17.5.1
F5 BIG-IP SSL Orchestrator>=17.1.0<=17.1.3
F5 BIG-IP SSL Orchestrator>=17.5.0<=17.5.1
F5 Big-ip Webaccelerator>=17.1.0<=17.1.3
F5 Big-ip Webaccelerator>=17.5.0<=17.5.1
F5 Big-ip Websafe>=17.1.0<=17.1.3
F5 Big-ip Websafe>=17.5.0<=17.5.1
F5 BIG-IP Access Policy Manager>=16.1.0<=16.1.6
F5 BIG-IP Advanced Firewall Manager>=16.1.0<=16.1.6
F5 Big-ip Advanced Web Application Firewall>=16.1.0<=16.1.6
F5 BIG-IP Analytics>=16.1.0<=16.1.6
F5 Big-ip Application Acceleration Manager>=16.1.0<=16.1.6
F5 BIG-IP Application Security Manager>=16.1.0<=16.1.6
F5 Big-ip Application Visibility And Reporting>=16.1.0<=16.1.6
F5 Big-ip Automation Toolchain>=16.1.0<=16.1.6
F5 Big-ip Carrier-grade Nat>=16.1.0<=16.1.6
F5 BIG-IP Container Ingress Services>=16.1.0<=16.1.6
F5 Big-ip Ddos Hybrid Defender>=16.1.0<=16.1.6
F5 Big-ip Domain Name System>=16.1.0<=16.1.6
F5 BIG-IP Edge Gateway>=16.1.0<=16.1.6
F5 Big-ip Fraud Protection Service>=16.1.0<=16.1.6
F5 Big-ip Global Traffic Manager>=16.1.0<=16.1.6
F5 Big-ip Link Controller>=16.1.0<=16.1.6
F5 Big-ip Local Traffic Manager>=16.1.0<=16.1.6
F5 Big-ip Policy Enforcement Manager>=16.1.0<=16.1.6
F5 BIG-IP SSL Orchestrator>=16.1.0<=16.1.6
F5 Big-ip Webaccelerator>=16.1.0<=16.1.6
F5 Big-ip Websafe>=16.1.0<=16.1.6
F5 BIG-IP Access Policy Manager=21.0.0
F5 BIG-IP Advanced Firewall Manager=21.0.0
F5 Big-ip Advanced Web Application Firewall=21.0.0
F5 BIG-IP Analytics=21.0.0
F5 Big-ip Application Acceleration Manager=21.0.0
F5 BIG-IP Application Security Manager=21.0.0
F5 Big-ip Application Visibility And Reporting=21.0.0
F5 Big-ip Automation Toolchain=21.0.0
F5 Big-ip Carrier-grade Nat=21.0.0
F5 BIG-IP Container Ingress Services=21.0.0
F5 Big-ip Ddos Hybrid Defender=21.0.0
F5 Big-ip Domain Name System=21.0.0
F5 BIG-IP Edge Gateway=21.0.0
F5 Big-ip Fraud Protection Service=21.0.0
F5 Big-ip Global Traffic Manager=21.0.0
F5 Big-ip Link Controller=21.0.0
F5 Big-ip Local Traffic Manager=21.0.0
F5 Big-ip Policy Enforcement Manager=21.0.0
F5 BIG-IP SSL Orchestrator=21.0.0
F5 Big-ip Webaccelerator=21.0.0
F5 Big-ip Websafe=21.0.0
Event History
May 13, 2026
CVE Published
via MITRE·02:12 PM
Data Sourced
via MITRE·02:12 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:16 PM
DescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-41218?
CVE-2026-41218 has a severity score of 8.7, indicating a high risk level.
2
How do I fix CVE-2026-41218?
To fix CVE-2026-41218, update your F5 BIG-IP software to the latest version that addresses this vulnerability.
3
What products are affected by CVE-2026-41218?
CVE-2026-41218 affects multiple F5 products including BIG-IP Access Policy Manager and BIG-IP Application Security Manager.
4
What impact does CVE-2026-41218 have on my system?
CVE-2026-41218 can cause the Traffic Management Microkernel (TMM) to terminate, impacting traffic flow.
5
What configurations are associated with CVE-2026-41218?
CVE-2026-41218 is linked to configurations of BIG-IP PEM iRules using specific commands such as CLASSIFICATION:: and CLASSIFY::.