PT-2026-40646 · F5 · Big-Ip

Published 2026-05-13 · Updated 2026-05-17 · CVE-2026-40423

Positive Technologies (AI Summary)

CVSS v3.1

7.5

High

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions F5 BIG-IP versions prior to 17.1.3.2 F5 BIG-IP versions prior to 17.5.1.6 F5 BIG-IP versions prior to 21.0.0.2

Description When a SIP (Session Initiation Protocol) profile is configured on a virtual server, undisclosed traffic can cause the Traffic Management Microkernel (TMM) to terminate. This occurs due to an issue with the allocation of resources within the TMM.

Recommendations Update to version 17.1.3.2 or later. Update to version 17.5.1.6 or later. Update to version 21.0.0.2 or later.

Fix

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

Related Identifiers

CVE-2026-40423

Affected Products

Big-Ip

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-40423 · Security Note
• https://my.f5.com/manage/s/article/K000161023 · Patch, Vendor Advisory
• https://twitter.com/f1tym1/status/2055991594021433512 · Twitter Post