Intelligence online17 sources monitored13 actively exploited 7d40 published 24hChecked recently
Vulnerability record

CVE-2026-3833

HighNo known exploitation

Patch status

No official fix confirmed yet

Until a fix ships, follow the vendor's mitigations, limit exposure of affected systems, and watch this record for a patch.

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.

Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.

Intelligence timeline

Developments from the last 30 days, newest first.

  1. CVSS scoredUpdate

    CVE-2026-3833 scored CVSS 7.4

    Basis: NIST National Vulnerability Database

  2. Disclosed

    VU#573195: Go, OpenSSL, Apple, LibreSSL, pyca, wolfSSL Name-Constraint Inconsistency in RFC 5280 Implementation

    Basis: CERT/CC Vulnerability Notes (CERT advisory)

Coverage

References