---
id: CVE-2026-42011
title: A flaw was found in gnutls
summary: >-
  A flaw was found in gnutls. This vulnerability occurs because permitted name
  constraints were incorrectly ignored when previous Certificate Authorities
  (CAs) only had excluded name constraints. A remote attacker could exploit this
  to byp…
severity: high
cvss: 7.4
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-295
published: '2026-05-07'
updated: '2026-06-26'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-42011'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:13274'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:20611'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:20612'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:20613'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:26319'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:26409'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:29197'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:30004'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-42011'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2467437'
    label: secalert@redhat.com
  - url: 'https://www.gnutls.org/security-new.html#GNUTLS-SA-2026-04-29-6'
    label: secalert@redhat.com
tags:
  - nvd
epss: 0.00475
epssPercentile: 0.40112
ingestedAt: '2026-06-26T16:43:13.639Z'
---

## Overview

A flaw was found in gnutls. This vulnerability occurs because permitted name constraints were incorrectly ignored when previous Certificate Authorities (CAs) only had excluded name constraints. A remote attacker could exploit this to bypass critical name constraint checks during certificate validation. This bypass could lead to the acceptance of invalid certificates, potentially enabling spoofing or man-in-the-middle attacks against affected systems.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.