CVE-2026-41218 BIG-IP PEM iRules vulnerability
Attackers can cause a denial of service by sending undisclosed traffic to BIG-IP PEM iRules, requiring specific iRule configurations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-41218?
CVE-2026-41218 is a high-severity use after free vulnerability in F5 Big-Ip Access Policy Manager, published on 13 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-416
Which versions are affected by CVE-2026-41218?
It affects 21 products.
Products include F5 Big-Ip Access Policy Manager, F5 Big-Ip Advanced Firewall Manager, F5 Big-Ip Advanced Web Application Firewall, F5 Big-Ip Analytics, F5 Big-Ip Application Acceleration Manager, F5 Big-Ip Application Security Manager and 15 more.
How do I fix CVE-2026-41218?
No fix has been published for CVE-2026-41218 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-41218 being exploited?
There is no known exploitation of CVE-2026-41218 in the wild and no public exploit code.
Other vulnerabilities in F5 Big-Ip Access Policy Manager
- CVE-2023-46747 F5 BIG-IP Configuration Utility Authentication Bypass
- CVE-2022-1388 F5 BIG-IP Missing Authentication
- CVE-2021-22986 F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution
- CVE-2021-22991 F5 BIG-IP Traffic Management Microkernel Buffer Overflow
- CVE-2020-5902 F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution
Sources
Also known as GHSA-65gg-93p6-xmj9.