What is CVE-2026-39455?

CVE-2026-39455 is a high-severity vulnerability in F5 Big-ip, classified under Missing Release of Resource after Effective Lifetime. CVSS score: 7.5/10. Published 2026-05-13.

How severe is CVE-2026-39455?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in F5 Big-ip

CVE-2026-39455

When the BIG-IP Configuration utility is configured to use Lightweight Directory Access Protocol (LDAP) authentication, undisclosed traffic can cause the httpd process to exhaust the available file descriptors. Note: Software versions whi…

EPSS: 0.001 (28.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

F5 Big-ip — versions 21.1.0, 21.0.0, 17.5.0

Weakness classification (CWE)

CWE-772 — Missing Release of Resource after Effective Lifetime

References

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

Frequently asked questions

What is CVE-2026-39455?: CVE-2026-39455 is a high-severity vulnerability in F5 Big-ip, classified under Missing Release of Resource after Effective Lifetime. CVSS score: 7.5/10. Published 2026-05-13.
How severe is CVE-2026-39455?: High severity. CVSS v3 base score is 7.5 out of 10.