What is CVE-2026-41957?

CVE-2026-41957 is a high-severity vulnerability in F5 Big-ip, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-05-13.

How severe is CVE-2026-41957?

High severity. CVSS v3 base score is 8.8 out of 10.

Deserialization in F5 Big-ip

CVE-2026-41957

An authenticated remote code execution vulnerability through undisclosed vectors exists in the BIG-IP and BIG-IQ Configuration utility. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Vulnerability class: Insecure Deserialization

EPSS: 0.007 (72.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

F5 Big-ip — versions 21.0.0, 17.5.0, 17.1.0
F5 Big-iq — versions 8.4.0

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

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

Frequently asked questions

What is CVE-2026-41957?: CVE-2026-41957 is a high-severity vulnerability in F5 Big-ip, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-05-13.
How severe is CVE-2026-41957?: High severity. CVSS v3 base score is 8.8 out of 10.