What is CVE-2026-42058?

CVE-2026-42058 is a medium-severity vulnerability in F5 Big-ip, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 4.3/10. Published 2026-05-13.

How severe is CVE-2026-42058?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in F5 Big-ip

CVE-2026-42058

An authenticated attacker's undisclosed requests to BIG-IP iControl REST can lead to an information leak of BIG-IP local user account names. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

EPSS: 0.001 (16.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

Affected products

F5 Big-ip — versions 21.1.0, 21.0.0, 17.5.0

Weakness classification (CWE)

CWE-732 — Incorrect Permission Assignment for Critical Resource

References

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

Frequently asked questions

What is CVE-2026-42058?: CVE-2026-42058 is a medium-severity vulnerability in F5 Big-ip, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 4.3/10. Published 2026-05-13.
How severe is CVE-2026-42058?: Medium severity. CVSS v3 base score is 4.3 out of 10.