CVE-2026-3833

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

0.6% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-04-30 18:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-11-05 22:18 UTC Last updatedMost recent change to the record

Details

Published

2026-04-30 18:16 UTC

Last modified

2026-11-05 22:18 UTC

Exploit probability

0.6% · EPSS, next 30 days

Weakness

CWE-178

Record status

Modified

Affected

• 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

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None