Infinite loop in BIG-IP - CVE-2026-42920
Published: May 14, 2026
Vulnerability identifier: #VU131399
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2026-42920
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: F5 Networks
Affected software:
BIG-IP
BIG-IP
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to loop with unreachable exit condition in the Client SSL profile when processing undisclosed traffic on a UDP virtual server with Allow Dynamic Record Sizing enabled. A remote attacker can send traffic to cause a denial of service.
Only the data plane is exposed; there is no control plane exposure. Traffic is disrupted while the TMM process restarts.
How to mitigate CVE-2026-42920
Install security update from vendor's website.