CVE-2026-3833

Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison

State: Published
Severity: 6.5 Medium
Published: Apr 30, 2026
Updated: Oct 14, 2026
Reserved: Mar 9, 2026

Description

A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically for `dNSName` (DNS) or `rfc822Name` (email) constraints within `excludedSubtrees` or `permittedSubtrees`. A remote attacker can exploit this by crafting a leaf certificate with casing differences in the Subject Alternative Name (SAN), leading to a policy bypass where a certificate that should be rejected is instead accepted. This could result in unauthorized access or information disclosure.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N	redhat

Weaknesses

CWE-178 Improper Handling of Case Sensitivity

Affected Products

Product	Versions
gnutls	before 3.8.13Affected
Red Hat Enterprise Linux 10Red Hat	0:3.8.10-4.el10_2 and laterNot affected
Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat	0:3.8.9-9.el10_0.19 and laterNot affected
Red Hat Enterprise Linux 7 Extended Lifecycle SupportRed Hat	0:3.3.29-9.el7_9.2 and laterNot affected
Red Hat Enterprise Linux 8Red Hat	0:3.6.16-8.el8_10.6 and laterNot affected
Red Hat Enterprise Linux 8Red Hat	0:3.6.16-8.el8_10.6 and laterNot affected
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportRed Hat	0:3.6.14-10.el8_4.1 and laterNot affected
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportRed Hat	0:4.13-3.el8_4.1 and laterNot affected
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnRed Hat	0:3.6.14-10.el8_4.1 and laterNot affected
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnRed Hat	0:4.13-3.el8_4.1 and laterNot affected
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRed Hat	0:3.6.16-5.el8_6.5 and laterNot affected
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportRed Hat	0:4.13-3.el8_6.2 and laterNot affected
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnRed Hat	0:3.6.16-5.el8_6.5 and laterNot affected
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnRed Hat	0:4.13-3.el8_6.2 and laterNot affected
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRed Hat	0:3.6.16-7.el8_8.4 and laterNot affected
Red Hat Enterprise Linux 8.8 Telecommunications Update ServiceRed Hat	0:4.13-4.el8_8.1 and laterNot affected
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRed Hat	0:3.6.16-7.el8_8.4 and laterNot affected
Red Hat Enterprise Linux 8.8 Update Services for SAP SolutionsRed Hat	0:4.13-4.el8_8.1 and laterNot affected
Red Hat Enterprise Linux 9Red Hat	0:3.8.10-4.el9_8 and laterNot affected
Red Hat Enterprise Linux 9Red Hat	0:3.8.10-4.el9_8 and laterNot affected
Red Hat Enterprise Linux 9.2 Update Services for SAP SolutionsRed Hat	0:3.7.6-21.el9_2.7 and laterNot affected
Red Hat Enterprise Linux 9.4 Update Services for SAP SolutionsRed Hat	0:3.8.3-4.el9_4.6 and laterNot affected
Red Hat Enterprise Linux 9.6 Extended Update SupportRed Hat	0:3.8.3-6.el9_6.4 and laterNot affected
Red Hat OpenShift Container Platform 4.12Red Hat	412.86.202608241157-0 and laterNot affected
Red Hat OpenShift Container Platform 4.13Red Hat	413.92.202609080414-0 and laterNot affected
Red Hat OpenShift Container Platform 4.14Red Hat	414.92.202609011250-0 and laterNot affected
Red Hat OpenShift Container Platform 4.15Red Hat	415.92.202609140326-0 and laterNot affected
Red Hat OpenShift Container Platform 4.16Red Hat	416.94.202609011112-0 and laterNot affected
Red Hat OpenShift Container Platform 4.17Red Hat	417.94.202608250221-0 and laterNot affected
Red Hat OpenShift Container Platform 4.18Red Hat	418.94.202609031320-0 and laterNot affected
Red Hat OpenShift Container Platform 4.19Red Hat	4.19.9.6.202608182320-0 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.17Red Hat	1791371080 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.17Red Hat	1791371069 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.17Red Hat	1791788287 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.17Red Hat	1791970484 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.18Red Hat	1791459707 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.18Red Hat	1791459711 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.18Red Hat	1791459759 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.18Red Hat	1789029076 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.18Red Hat	1791966259 and laterNot affected
Cert Manager support for Red Hat OpenShift release 1.20Red Hat	1790598593 and laterNot affected
Red Hat Discovery 2Red Hat	1782159791 and laterNot affected
Red Hat Discovery 2Red Hat	1782166952 and laterNot affected
Red Hat Hardened ImagesRed Hat	3.8.13-1.hum1 and laterNot affected
Red Hat OpenShift AI 3.4Red Hat	1790703542 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1781525684 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1781525671 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1781525693 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1781525739 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1787241211 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1787135742 and laterNot affected
Red Hat Update Infrastructure 5Red Hat	1787241260 and laterNot affected
Red Hat Enterprise Linux 6Red Hat
Red Hat OpenShift Container Platform 4Red Hat

References

RHSA-2026:13274vendor-advisory
RHSA-2026:20611vendor-advisory
RHSA-2026:20612vendor-advisory
RHSA-2026:20613vendor-advisory
RHSA-2026:26319vendor-advisory
RHSA-2026:26409vendor-advisory
RHSA-2026:29197vendor-advisory
RHSA-2026:30004vendor-advisory
RHSA-2026:30849vendor-advisory
RHSA-2026:30850vendor-advisory
RHSA-2026:32962vendor-advisory
RHSA-2026:33125vendor-advisory
RHSA-2026:41921vendor-advisory
RHSA-2026:43575vendor-advisory
RHSA-2026:57402vendor-advisory
RHSA-2026:58981vendor-advisory
RHSA-2026:59831vendor-advisory
RHSA-2026:60019vendor-advisory
RHSA-2026:62409vendor-advisory
RHSA-2026:62549vendor-advisory
RHSA-2026:65839vendor-advisory
RHSA-2026:65851vendor-advisory
RHSA-2026:67857vendor-advisory
RHSA-2026:72502vendor-advisory
RHSA-2026:74674vendor-advisory
RHSA-2026:82304vendor-advisory
RHSA-2026:82322vendor-advisory
RHSA-2026:82347vendor-advisory
RHSA-2026:82354vendor-advisory
RHSA-2026:82372vendor-advisory
RHSA-2026:82857vendor-advisory
RHSA-2026:82888vendor-advisory
https://access.redhat.com/security/cve/CVE-2026-3833vdb-entry
RHBZ#2445763issue-tracking
https://gitlab.com/gnutls/gnutls/-/issues/1803

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