---
id: CVE-2026-123578
title: Hickory DNS 0.26.0 before 0.26.2 Response Validation Bypass via QDCOUNT=0
summary: >-
  Hickory DNS hickory-net 0.26.0 before 0.26.2 and hickory-proto 0.25.0 through
  0.25.2 skip the check that a UDP response's question section matches the query
  when the response has an empty question section (QDCOUNT=0), and also skip the
  c…
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'
cvssSource: cna
cwe:
  - CWE-290
vendor: hickory-dns
product: hickory-dns
affected:
  - hickory-dns >= 0.26.0 < 0.26.2
  - hickory-dns >= 0.25.0 <= 0.25.2
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:38:13.386Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123578'
references:
  - url: >-
      https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3w89-7rx5-hpwx
    label: GitHub Security Advisory (GHSA-3w89-7rx5-hpwx)
  - url: >-
      https://www.vulncheck.com/advisories/hickory-dns-0.26.0-before-0.26.2-response-validation-bypass-via-qdcount-0
    label: >-
      VulnCheck Advisory: Hickory DNS 0.26.0 before 0.26.2 Response Validation
      Bypass via QDCOUNT=0
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.653Z'
---

## Overview

Hickory DNS hickory-net 0.26.0 before 0.26.2 and hickory-proto 0.25.0 through 0.25.2 skip the check that a UDP response's question section matches the query when the response has an empty question section (QDCOUNT=0), and also skip the case-randomization check. Remote attackers able to inject spoofed UDP responses can send QDCOUNT=0 responses to bypass these checks, weakening defenses against DNS spoofing.

## Affected

- `hickory-dns >= 0.26.0 < 0.26.2`
- `hickory-dns >= 0.25.0 <= 0.25.2`

## Remediation

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