---
id: CVE-2026-123607
title: Hickory DNS NSEC3 Closest-Encloser Proof Unbounded Loop Denial of Service
summary: >-
  Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before
  0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3
  closest-encloser proof validation when the SOA owner is not an ancestor of the
  QNAME. …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-835
vendor: hickory-dns
product: hickory-dns
affected:
  - hickory-dns >= 0.25.0-alpha.3 <= 0.25.2
  - hickory-dns >= 0.26.0-alpha.1 < 0.26.1
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:38:33.416Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123607'
references:
  - url: >-
      https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3v94-mw7p-v465
    label: GitHub Security Advisory (GHSA-3v94-mw7p-v465)
  - url: >-
      https://www.vulncheck.com/advisories/hickory-dns-nsec3-closest-encloser-proof-unbounded-loop-denial-of-service
    label: >-
      VulnCheck Advisory: Hickory DNS NSEC3 Closest-Encloser Proof Unbounded
      Loop Denial of Service
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.640Z'
---

## Overview

Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.

## Affected

- `hickory-dns >= 0.25.0-alpha.3 <= 0.25.2`
- `hickory-dns >= 0.26.0-alpha.1 < 0.26.1`

## Remediation

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