CVE-2026-3833: Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison

Published Mar 9, 2026
·
Updated

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.

Affected Software

10 affected componentsFixes available
GNUTLS GNUTLS
GNU GnuTLS
redhat Hardened Images
redhat OpenShift Container Platform=4.0
redhat Enterprise Linux=6.0
redhat Enterprise Linux=7.0
redhat Enterprise Linux=8.0
redhat Enterprise Linux=9.0
redhat Enterprise Linux=10.0
debian/gnutls28<=3.7.1-5+deb11u5, <=3.7.1-5+deb11u9, <=3.7.9-2+deb12u6, <=3.8.9-3+deb13u3
3.7.9-2+deb12u73.8.9-3+deb13u43.8.13-1

Event History

Mar 9, 2026
Data Sourced
via Red Hat·02:03 PM
DescriptionSeverityAffected Software
Apr 30, 2026
CVE Published
via MITRE·05:37 PM
Data Sourced
via MITRE·05:37 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·06:16 PM
DescriptionSeverityWeaknessAffected Software
May 20, 2026
Data Sourced
via Launchpad·02:42 PM
Description
Data Sourced
via Debian·02:42 PM
DescriptionAffected Software
May 22, 2026
Data Sourced
via Ubuntu·02:43 PM
RemedyDescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-3833?

CVE-2026-3833 has a moderate severity rating due to potential impact on name constraints processing.

2

How do I fix CVE-2026-3833?

To fix CVE-2026-3833, update GnuTLS to the latest version where the vulnerability has been patched.

3

What is the impact of CVE-2026-3833?

The impact of CVE-2026-3833 includes the possibility of policy bypass due to incorrect case-sensitive comparisons.

4

Which software is affected by CVE-2026-3833?

CVE-2026-3833 affects GnuTLS, particularly versions prior to the fix addressing the vulnerability.

5

Is there a workaround for CVE-2026-3833?

There are no known workarounds for CVE-2026-3833; updating GnuTLS is the recommended approach.

Contact

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