CVE-2026-42012

HIGH

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

Title source: cna

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 (17)

Core 17

Core References

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:26319

https://access.redhat.com/errata/RHSA-2026:26319

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:26409

https://access.redhat.com/errata/RHSA-2026:26409

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:29197

https://access.redhat.com/errata/RHSA-2026:29197

https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-7

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-2026:30004

https://access.redhat.com/errata/RHSA-2026:30004

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20611

https://access.redhat.com/errata/RHSA-2026:20611

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:30849

https://access.redhat.com/errata/RHSA-2026:30849

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:30850

https://access.redhat.com/errata/RHSA-2026:30850

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:32962

https://access.redhat.com/errata/RHSA-2026:32962

Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat

RHBZ#2467441

https://bugzilla.redhat.com/show_bug.cgi?id=2467441

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:13274

https://access.redhat.com/errata/RHSA-2026:13274

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:33125

https://access.redhat.com/errata/RHSA-2026:33125

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:41921

https://access.redhat.com/errata/RHSA-2026:41921

Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat

https://access.redhat.com/security/cve/CVE-2026-42012

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:43575

https://access.redhat.com/errata/RHSA-2026:43575

Scores

CVSS v3 7.1

EPSS 0.0035

EPSS Percentile 28.1%

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 (34)

Red Hat/Red Hat Discovery 2 1782159791

Red Hat/Red Hat Discovery 2 1782166952

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 10.0 Extended Update Support 0:3.8.9-9.el10_0.19

Red Hat/Red Hat Enterprise Linux 6

Red Hat/Red Hat Enterprise Linux 7

Red Hat/Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:3.3.29-9.el7_9.2

Red Hat/Red Hat Enterprise Linux 8

Red Hat/Red Hat Enterprise Linux 8 0:3.6.16-8.el8_10.6

... and 24 more

Published May 26, 2026

Tracked Since May 27, 2026