CVE-2026-123585
Received Received - Intake

Hickory DNS resolver CNAME query amplification vulnerability

Publication date: 2026-11-08

Last updated on: 2026-11-08

Assigner: VulnCheck

Description
The hickory-resolver component of Hickory DNS 0.25.0 before 0.26.2 follows irrelevant CNAME records when resolving recursive queries, sending queries that are unnecessary to answer the original request. Attackers controlling DNS responses can include CNAME records in the authority or additional sections, or outside the original query name's CNAME chain, causing excess resolver queries and increased query amplification.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-11-08
Last Modified
2026-11-08
Generated
2026-11-08
AI Q&A
2026-11-08
EPSS Evaluated
N/A
NVD
CVE-2026-123585
EUVD
EUVD-2026-119344

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
hickory dns to 0.26.2 (exc)

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-400 The product does not properly control the allocation and maintenance of a limited resource.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

The hickory-resolver in Hickory DNS versions before 0.26.2 incorrectly processes CNAME records during recursive DNS queries. Instead of ignoring irrelevant CNAME records, it follows them even when they don't contribute to resolving the original query. Attackers can exploit this by injecting CNAME records into DNS responses, forcing the resolver to perform unnecessary additional queries. This leads to query amplification and potential denial-of-service conditions.

Impact Analysis

This vulnerability can cause increased DNS query traffic, leading to performance degradation or service disruption for DNS servers using affected Hickory DNS versions. Attackers may leverage it to amplify denial-of-service attacks by forcing resolvers to send excessive queries to legitimate DNS servers.

Mitigation Strategies

Upgrade Hickory DNS to version 0.26.2 or later to address the CNAME record handling issue in the hickory-resolver component.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-123585. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart

Security Radar

News mentioning this vulnerability
Loading related security news...