CVE-2026-42013 HIGH

CVE-2026-42013: Gnutls: gnutls: certificate validation bypass due to oversized subject alternative name

Vendor Red Hat
Product Red Hat Enterprise Linux 6
Weakness CWE-295
Published May 26, 2026
Last update June 30, 2026

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N

What the vulnerability does

01Description

A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.

Key dates

02Disclosure timeline

May 26, 2026 CVE published
June 30, 2026 Record updated