Bug 2467441 (CVE-2026-42012)

Summary:	CVE-2026-42012 gnutls: gnutls: Certificate validation bypass due to improper handling of URI and SRV SANs
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, kshier, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, stcannon, suppawar, teagle, vlaad, watson-tool-maintainers, yguenane
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	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.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-06 19:17:52 UTC

libgnutls: Suppress CN fallback in presence of URI and SRV SAN
   Certificates containing URI or SRV Subject Alternative Names no longer fall back to checking DNS hostnames against Common Name to avoid potential misuse of such certificates beyond their original purpose.

Comment 3 errata-xmlrpc 2026-06-16 16:39:25 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10.0 Extended Update Support

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

Comment 5 errata-xmlrpc 2026-06-25 18:07:37 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.6 Extended Update Support

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

Comment 6 errata-xmlrpc 2026-06-29 02:30:17 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
  Red Hat Enterprise Linux 8.8 Telecommunications Update Service

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

Comment 7 errata-xmlrpc 2026-06-29 02:48:32 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On

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

Comment 8 errata-xmlrpc 2026-06-29 09:47:21 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions

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

Comment 9 errata-xmlrpc 2026-06-29 15:07:31 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
  Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On

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

Comment 10 errata-xmlrpc 2026-07-20 06:28:02 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions

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

Comment 11 errata-xmlrpc 2026-07-22 14:35:16 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7 Extended Lifecycle Support

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