CVE-2026-40423 BIG-IP SIP profile vulnerability

What is CVE-2026-40423?

CVE-2026-40423 is a high-severity denial of service 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 a SIP profile is configured on a virtual server, 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-770

Which versions are affected by CVE-2026-40423?

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-2026-40423?

No fix has been published for CVE-2026-40423 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-40423 being exploited?

There is no known exploitation of CVE-2026-40423 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 Exploited Critical 9.8
• CVE-2022-1388 F5 BIG-IP Missing Authentication Exploited Critical 9.8
• CVE-2021-22986 F5 BIG-IP and BIG-IQ Centralized Management iControl REST Remote Code Execution Exploited Critical 9.8
• CVE-2021-22991 F5 BIG-IP Traffic Management Microkernel Buffer Overflow Exploited Critical 9.8
• CVE-2020-5902 F5 BIG-IP Traffic Management User Interface (TMUI) Remote Code Execution Exploited Critical 9.8

All F5 Big-Ip Access Policy Manager vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-3f74-cm4w-65c4.