3.7

CVE-2026-77205: the libreswan project libreswan

CVSS: 3.7v3.1LowAwaiting analysis
AliasesDEBIAN-CVE-2026-77205UBUNTU-CVE-2026-77205
Published 13-10-2026Last modified 16-10-2026
Open JSON

Vulnerability summary

CVE-2026-77205 is a low (CVSS 3.7) vulnerability in the libreswan project libreswan. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.4% of scored vulnerabilities.

Overall risk
15/100
0100
Low · default modelHow is this calculated?
CVSS score
3.7/10
010
Low · v3.1 (CVE.org)
EPSS score
0.18%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 13-10-2026
    PublishedVulnerability first disclosed.
  2. 16-10-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.18%

Chance of exploitation in the next 30 days

Percentile

7%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

14-10-202619-10-2026
EPSS score
0.18%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • libreswanAll versions (No fix recorded)
The libreswan project1 product
Ubuntu1 product
  • libreswanAll versions (No fix recorded)

3 vendors · 3 products

References

6 links