CVE intelligence

CVE-2026-42013

Vulnerability intelligence

Published May 26, 2026Sources checked Sep 27, 2026

8.2HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-42013 and is rated High severity with a CVSS score of 8.2. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.6%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-42013?

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.