What is CVE-2026-77205?

CVE-2026-77205 is a low-severity vulnerability in The Libreswan Project, classified under Missing Release of Resource after Effective Lifetime. CVSS score: 3.7/10. Published 2026-10-13.

How severe is CVE-2026-77205?

Low severity. CVSS v3 base score is 3.7 out of 10.

Vulnerability in The Libreswan Project

CVE-2026-77205

Libreswan in FIPS mode has a vulnerability where badly formed received certificates are rejected, but not deleted from the NSS cache. As a result, any real certificates with the same serial number are rejected as well. This can be abused to lock out legitimate peers from connecting. The add_decoded_cert() function missed a call to CERT_DestroyCertificate() due to an incorrect fix for CVE-2026-14957. Sending bogus certificates with new serial numbers could prevent the real certificates with those serial numbers from connecting until the service has restarted.

Published 2026-10-13.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

The Libreswan Project

Weakness classification (CWE)

CWE-772 — Missing Release of Resource after Effective Lifetime

References

d42dc95b-23f1-4e06-9076-20753a0fb0df (vendor-advisory)
d42dc95b-23f1-4e06-9076-20753a0fb0df (patch)
d42dc95b-23f1-4e06-9076-20753a0fb0df (related)

Frequently asked questions

What is CVE-2026-77205?: CVE-2026-77205 is a low-severity vulnerability in The Libreswan Project, classified under Missing Release of Resource after Effective Lifetime. CVSS score: 3.7/10. Published 2026-10-13.
How severe is CVE-2026-77205?: Low severity. CVSS v3 base score is 3.7 out of 10.