---
id: CVE-2026-123571
title: Hickory DNS from 0.26.0 before 0.26.2 Panic via TSIG RDATA Decoding
summary: >-
  Hickory DNS from 0.26.0 before 0.26.2 contains an integer underflow
  vulnerability in TSIG RDATA decoding that allows remote attackers to trigger a
  panic via malformed records. Attackers can send a crafted TSIG record in DNS
  wire format t…
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-191
vendor: hickory-dns
product: hickory-dns
affected:
  - hickory-dns >= 0.26.0 < 0.26.2
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:38:08.593Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123571'
references:
  - url: >-
      https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-x962-5xwx-fr8x
    label: GitHub Security Advisory (GHSA-x962-5xwx-fr8x)
  - url: >-
      https://www.vulncheck.com/advisories/hickory-dns-from-0.26.0-before-0.26.2-panic-via-tsig-rdata-decoding
    label: >-
      VulnCheck Advisory: Hickory DNS from 0.26.0 before 0.26.2 Panic via TSIG
      RDATA Decoding
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.658Z'
---

## Overview

Hickory DNS from 0.26.0 before 0.26.2 contains an integer underflow vulnerability in TSIG RDATA decoding that allows remote attackers to trigger a panic via malformed records. Attackers can send a crafted TSIG record in DNS wire format to cause unchecked subtraction underflow, crashing builds with overflow checks enabled and causing denial of service.

## Affected

- `hickory-dns >= 0.26.0 < 0.26.2`

## Remediation

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