---
id: CVE-2026-123594
title: >-
  Hickory DNS through 0.26.0-alpha.1 DNSSEC NSEC Validation Bypass for Empty
  Non-Terminals
summary: >-
  Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1
  before 0.26.2 contain an NSEC validation flaw that returns a secure proof for
  NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict
  descend…
severity: medium
cvss: 4.8
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-345
vendor: hickory-dns
product: hickory-dns
affected:
  - hickory-dns <= 0.26.0-alpha.1
  - hickory-dns >= 0.26.0-beta.1 < 0.26.2
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:38:24.397Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123594'
references:
  - url: >-
      https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-86vr-jm6c-7cpg
    label: GitHub Security Advisory (GHSA-86vr-jm6c-7cpg)
  - url: >-
      https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-nsec-validation-bypass-for-empty-non-terminals
    label: >-
      VulnCheck Advisory: Hickory DNS through 0.26.0-alpha.1 DNSSEC NSEC
      Validation Bypass for Empty Non-Terminals
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.644Z'
---

## Overview

Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.

## Affected

- `hickory-dns <= 0.26.0-alpha.1`
- `hickory-dns >= 0.26.0-beta.1 < 0.26.2`

## Remediation

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