Traffic Management Microkernel Vulnerability in F5 Networks Product
CVE-2026-40423

8.7HIGH

Key Information:

Vendor

F5
Status
Big-ip
Vendor
CVE Published:
13 May 2026

What is CVE-2026-40423?

When a SIP profile is set up on a virtual server, the Traffic Management Microkernel (TMM) may unexpectedly terminate due to undisclosed traffic. This can lead to a denial of service for applications reliant on stable virtual server operations. It is essential for users to check their software versions for updates, especially those that have not reached End of Technical Support. For further guidance and patch details, refer to the vendor's advisory.

Affected Version(s)

BIG-IP 21.0.0 < 21.0.0.2

BIG-IP 17.5.0 < 17.5.1.6

BIG-IP 17.1.0 < 17.1.3.2

References

https://my.f5.com/manage/s/article/K000161023
vendor-advisorypatch

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

F5
.