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

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.

Timeline

Scores

EPSS (exploitation in 30 days)

0.37% · top 68% of all CVEs (10 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.

Affected products

• gnutls

  • affected 0

• Red Hat · Red Hat Enterprise Linux 10

  • unaffected 0:3.8.10-4.el10_2 – < *

• Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support

  • unaffected 0:3.8.9-9.el10_0.19 – < *

• Red Hat · Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION

  • unaffected 0:2.12.23-22.el6_10.1 – < *

• Red Hat · Red Hat Enterprise Linux 7 Extended Lifecycle Support

  • unaffected 0:3.3.29-9.el7_9.2 – < *

• Red Hat · Red Hat Enterprise Linux 8

  • unaffected 0:3.6.16-8.el8_10.6 – < *

• Red Hat · Red Hat Enterprise Linux 8

  • unaffected 0:3.6.16-8.el8_10.6 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

  • unaffected 0:3.6.14-10.el8_4.1 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support

  • unaffected 0:4.13-3.el8_4.1 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

  • unaffected 0:3.6.14-10.el8_4.1 – < *

• Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

  • unaffected 0:4.13-3.el8_4.1 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

  • unaffected 0:3.6.16-5.el8_6.5 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support

  • unaffected 0:4.13-3.el8_6.2 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

  • unaffected 0:3.6.16-5.el8_6.5 – < *

• Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

  • unaffected 0:4.13-3.el8_6.2 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service

  • unaffected 0:3.6.16-7.el8_8.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service

  • unaffected 0:4.13-4.el8_8.1 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

  • unaffected 0:3.6.16-7.el8_8.4 – < *

• Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions

  • unaffected 0:4.13-4.el8_8.1 – < *

• Red Hat · Red Hat Enterprise Linux 9

  • unaffected 0:3.8.10-4.el9_8 – < *

• Red Hat · Red Hat Enterprise Linux 9

  • unaffected 0:3.8.10-4.el9_8 – < *

• Red Hat · Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

  • unaffected 0:3.7.6-21.el9_2.7 – < *

• Red Hat · Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

  • unaffected 0:3.8.3-4.el9_4.6 – < *

• Red Hat · Red Hat Enterprise Linux 9.6 Extended Update Support

  • unaffected 0:3.8.3-6.el9_6.4 – < *

• Red Hat · Red Hat OpenShift Container Platform 4.20

  • unaffected 4.20.9.6.202610242033-0 – < *

• Red Hat · Red Hat OpenShift Container Platform 4.21

  • unaffected 4.21.9.6.202610241345-0 – < *

• Red Hat · Red Hat OpenShift Container Platform 4.22

  • unaffected 4.22.9.8.202610241758-0 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.17

  • unaffected 1791371080 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.17

  • unaffected 1791371069 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.17

  • unaffected 1791788287 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.17

  • unaffected 1791970484 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.18

  • unaffected 1791459707 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.18

  • unaffected 1791459711 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.18

  • unaffected 1791459759 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.18

  • unaffected 1789029076 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.18

  • unaffected 1791966259 – < *

• Red Hat · Cert Manager support for Red Hat OpenShift release 1.20

  • unaffected 1790598593 – < *

• Red Hat · Red Hat Discovery 2

  • unaffected 1782159791 – < *

• Red Hat · Red Hat Discovery 2

  • unaffected 1782166952 – < *

• Red Hat · Red Hat Hardened Images

  • unaffected 3.8.13-1.hum1 – < *

• Red Hat · Red Hat OpenShift AI 3.4

  • unaffected 1790703542 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1781525684 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1781525671 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1781525693 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1781525739 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1787241211 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1787135742 – < *

• Red Hat · Red Hat Update Infrastructure 5

  • unaffected 1787241260 – < *

• Red Hat · Red Hat OpenShift Container Platform 4

  All versions: unaffected

• Red Hat · Red Hat OpenShift Container Platform 4

  All versions: affected

• Red Hat · Red Hat OpenShift Container Platform 5

  All versions: affected

What to do

Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-32010 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-42012](https://cveledger.app/badge/CVE-2026-42012.svg)](https://cveledger.app/cve/CVE-2026-42012)

Record last updated 3 Nov 2026, 08:27 UTC.