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CVE-2026-3833

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

Published: Apr 30, 2026Updated: Jun 30, 2026 Sources: CVE List NVD BDUCWE-178
6.5MEDIUM
NVD MITRE
EPSS Score
0.6%
Top 57.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-178

Affected Products

Red Hat Inc.
commercial·USaka redhat, Red Hat
hardened imagesOn-prem
Operating Systems / linux-distro
openshift container platformOn-prem
Operating Systems / linux-distro
Red Hat Enterprise Linux 10On-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 10.0 Extended Update SupportOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-OnOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update SupportOn-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-OnOn-premOS
Operating Systems / linux-distro
gnu
oss-project·USaka g. nu
gnutls
OSS Libraries
Novell Inc.
commercial·US
openSUSE TumbleweedOn-prem
Operating Systems / linux-distro
Сообщество свободного программного обеспечения
oss-projectaka fsf
Debian GNU/LinuxOn-premOS
Operating Systems / linux-distro
АО «ИВК»
commercial·RUaka ivk
АЛЬТ СП 10On-premOS
Operating Systems / linux-distro
Free Software Foundation, Inc.
oss-project·USaka free software foundation, fsf
GnuTLS
OSS Libraries
and 17 more affected products View all →

Exploitability

Official Patch Available
Workaround Available
Scannable·OpenVAS
Is your org exposed to CVE-2026-3833?We can run the check for you — a free external exposure review, no install. Check my exposure

References

https://access.redhat.com/errata/RHSA-2026:13274
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:20611
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:20612
access.redhat.com
and 17 more references View all →
News mentions
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