---
id: CVE-2026-88648
title: >-
  Incomplete X.509 implementation in GnuTLS v3.8.13 allows attackers controlling
  a subordinate Certificate Authority to bypass cross-domain PKI restrictions
  and issue unauthorized certificates.
summary: >-
  Incomplete X.509 implementation in GnuTLS v3.8.13 allows attackers controlling
  a subordinate Certificate Authority to bypass cross-domain PKI restrictions
  and issue unauthorized certificates.
severity: none
published: '2026-10-08'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T21:33:42.423'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88648'
references:
  - url: 'https://gist.github.com/lkloliver/1f2a97cb8d0b31aa27b6bd0354358d7d'
    label: cve@mitre.org
  - url: 'https://www.rfc-editor.org/rfc/rfc5280#section-4.2.1.10'
    label: cve@mitre.org
  - url: 'https://www.rfc-editor.org/rfc/rfc5280#section-6.1.4'
    label: cve@mitre.org
tags:
  - nvd
ingestedAt: '2026-10-08T20:06:22.191Z'
---

## Overview

Incomplete X.509 implementation in GnuTLS v3.8.13 allows attackers controlling a subordinate Certificate Authority to bypass cross-domain PKI restrictions and issue unauthorized certificates.

## Remediation

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