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CVE-2026-41956 F5 CVE debrief

CVE-2026-41956 is a high-severity vulnerability in F5 BIG-IP Traffic Management Microkernel. When a classification profile is configured on a UDP virtual server, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate. This issue affects multiple F5 BIG-IP products and versions. The Common Vulnerability Scoring System (CVSS) score for this vulnerability is 8.7, indicating a high severity. F5 has provided mitigation guidance for this issue.

Vendor
F5
Product
BIG-IP
CVSS
HIGH 8.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-13
Original CVE updated
2026-06-24
Advisory published
2026-05-13
Advisory updated
2026-06-24

Who should care

Organizations using F5 BIG-IP products, particularly those with UDP virtual servers configured with classification profiles, should prioritize patching this vulnerability. The vulnerability's high CVSS score and potential for denial-of-service attacks make it a critical concern for network administrators and security teams. Additionally, organizations with F5 BIG-IP versions 16.1.0 through 17.1.3 and 17.5.0 through 17.5.1 are affected and should take immediate action.

Technical summary

The vulnerability exists in the Traffic Management Microkernel (TMM) of F5 BIG-IP products when a classification profile is configured on a UDP virtual server. Undisclosed requests can cause the TMM to terminate, leading to a denial-of-service condition. The issue affects various F5 BIG-IP products, including BIG-IP Access Policy Manager, BIG-IP Advanced Firewall Manager, and others. The CVSS vector for this vulnerability is 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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

Defensive priority

This vulnerability has a high CVSS score of 8.7 and can lead to a denial-of-service condition, making it a high-priority issue for F5 BIG-IP administrators. Immediate patching or mitigation is recommended to prevent potential attacks.

Recommended defensive actions

  • Apply the patches provided by F5 for the affected BIG-IP versions.
  • Implement the mitigation guidance provided by F5, as referenced in K000158038.
  • Conduct an inventory check to identify all affected F5 BIG-IP systems in the environment.
  • Prioritize patching for BIG-IP systems with UDP virtual servers configured with classification profiles.
  • Monitor network traffic and system logs for potential exploitation attempts.

Evidence notes

The CVE-2026-41956 record and NVD detail provide official information about the vulnerability. F5's mitigation guidance is available through their support portal. The vulnerability affects multiple F5 BIG-IP products and versions, as listed in the CVE and NVD records.

Official resources

This article was generated with AI assistance based on the supplied source corpus.