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


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.35% (28th percentile)

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  • Snyk IDSNYK-UBUNTU2004-GNUTLS28-16355189
  • published15 Jul 2026
  • disclosed26 May 2026

Introduced: 26 May 2026

CVE-2026-42012  (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. A remote attacker could exploit this vulnerability by presenting a specially crafted certificate that contains Uniform Resource Identifier (URI) or Service (SRV) Subject Alternative Names (SANs). This could cause the certificate validation process to incorrectly fall back to checking DNS hostnames against the Common Name (CN), potentially allowing the attacker to spoof legitimate services or intercept sensitive information.

CVSS Base Scores

version 3.1