Use-after-free in BIG-IP - CVE-2026-41218
Published: May 14, 2026
Vulnerability identifier: #VU131400
CSH Severity: Medium
CVSS v4: 8.7 [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]
CVE-ID: CVE-2026-41218
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in BIG-IP PEM data plane when processing undisclosed traffic on a virtual server with PEM iRules configured. A remote attacker can send traffic to cause a denial of service.
This issue affects the data plane only and has no control plane exposure.
Affected software
BIG-IP
How to mitigate CVE-2026-41218
Install security update from vendor's website.
BIG-IP - addressed in versions 17.1.3.1, 17.5.1.4, 21.0.0.1