CVE-2026-3833

6.5 MEDIUM
Published: April 30, 2026 Modified: June 30, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:13274
Source: secalert@redhat.com
Issue Tracking Third Party Advisory
https://access.redhat.com/security/cve/CVE-2026-3833
Source: secalert@redhat.com
Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2445763
Source: secalert@redhat.com
Issue Tracking Third Party Advisory
https://gitlab.com/gnutls/gnutls/-/issues/1803
Source: secalert@redhat.com
Exploit Issue Tracking Vendor Advisory
https://gitlab.com/gnutls/gnutls/-/issues/1803
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Issue Tracking Vendor Advisory

16 reference(s) from NVD

Quick Stats

CVSS v3 Score
6.5 / 10.0
EPSS (Exploit Probability)
0.6%
43th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

redhat gnu