CVE-2026-3833

medium

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.

References

https://gitlab.com/gnutls/gnutls/-/issues/1803

https://bugzilla.redhat.com/show_bug.cgi?id=2445763

https://access.redhat.com/security/cve/CVE-2026-3833

Details

Source: Mitre, NVD

Published: 2026-04-30

Updated: 2026-04-30

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Severity: Medium