What is CVE-2026-42406?

CVE-2026-42406 is a high-severity vulnerability in F5 Big-ip, classified under Privilege Defined With Unsafe Actions. CVSS score: 8.7/10. Published 2026-05-13.

How severe is CVE-2026-42406?

High severity. CVSS v3 base score is 8.7 out of 10.

Privilege escalation in F5 Big-ip

CVE-2026-42406

A vulnerability exists in BIG-IP and BIG-IQ systems where a highly privileged, authenticated attacker with at least the Certificate Manager role can modify configuration objects that allow running arbitrary commands. Note: Software ver…

EPSS: 0.000 (11.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N.

Affected products

F5 Big-ip — versions 21.1.0, 21.0.0, 17.5.0
F5 Big-iq — versions 8.4.0

Weakness classification (CWE)

CWE-267 — Privilege Defined With Unsafe Actions

References

f5sirt@f5.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-42406?: CVE-2026-42406 is a high-severity vulnerability in F5 Big-ip, classified under Privilege Defined With Unsafe Actions. CVSS score: 8.7/10. Published 2026-05-13.
How severe is CVE-2026-42406?: High severity. CVSS v3 base score is 8.7 out of 10.