Improper Certificate Validation Affecting gnutls28 package, versions <3.6.13-2ubuntu1.12+esm3


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

Social Trends
EPSS
0.48% (38th percentile)

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  • Snyk IDSNYK-UBUNTU2004-GNUTLS28-16355231
  • published15 Jul 2026
  • disclosed7 May 2026

Introduced: 7 May 2026

CVE-2026-42011  (opens in a new tab)
CWE-295  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 gnutls28 to version 3.6.13-2ubuntu1.12+esm3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream gnutls28 package and not the gnutls28 package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were incorrectly ignored when previous Certificate Authorities (CAs) only had excluded name constraints. A remote attacker could exploit this to bypass critical name constraint checks during certificate validation. This bypass could lead to the acceptance of invalid certificates, potentially enabling spoofing or man-in-the-middle attacks against affected systems.

CVSS Base Scores

version 3.1