CVE-2026-42012

HIGH

Gnutls: gnutls: certificate validation bypass due to improper handling of uri and srv sans

Title source: cna
STIX 2.1

Description

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.

References (5)

Core 5
Core References
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:20612
https://access.redhat.com/errata/RHSA-2026:20612
Vendor Advisory vendor-advisory x_refsource_redhat
https://access.redhat.com/errata/RHSA-2026:20613
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:20611
https://access.redhat.com/errata/RHSA-2026:20611
Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-42012
Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat
RHBZ#2467441
https://bugzilla.redhat.com/show_bug.cgi?id=2467441

Scores

CVSS v3 7.1
EPSS 0.0029
EPSS Percentile 20.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-295
Status published
Products (10)
Red Hat/Red Hat Enterprise Linux 10
Red Hat/Red Hat Enterprise Linux 10 0:3.8.10-4.el10_2
Red Hat/Red Hat Enterprise Linux 6
Red Hat/Red Hat Enterprise Linux 7
Red Hat/Red Hat Enterprise Linux 8
Red Hat/Red Hat Enterprise Linux 8 0:3.6.16-8.el8_10.6
Red Hat/Red Hat Enterprise Linux 9
Red Hat/Red Hat Enterprise Linux 9 0:3.8.10-4.el9_8
Red Hat/Red Hat Hardened Images
Red Hat/Red Hat OpenShift Container Platform 4
Published May 26, 2026
Tracked Since May 27, 2026