CVE-2026-123584
Received Received - Intake

DNS Parsing Failure in Hickory DNS Causes Denial of Service

Publication date: 2026-11-08

Last updated on: 2026-11-08

Assigner: VulnCheck

Description
The hickory-net crate in Hickory DNS 0.26.0 before 0.26.2 stops listening and returns an error when a client UDP connection receives a datagram that cannot be parsed as a DNS message. Remote attackers who guess the query's source port, without knowing the transaction ID, can spoof malformed responses to abort client queries, causing denial of service.

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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-2026-123584
EUVD
EUVD-2026-119343

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
hickory_dns hickory_net to 0.26.2 (exc)

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-696 The product performs multiple related behaviors, but the behaviors are performed in the wrong order in ways that may produce resultant weaknesses.

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Executive Summary

This vulnerability affects the hickory-net crate in Hickory DNS versions 0.26.0 before 0.26.2. When a client UDP connection receives a datagram that cannot be parsed as a DNS message, the system stops listening and returns an error. Attackers can exploit this by guessing the source port of a query and sending malformed responses to abort client queries, leading to a denial of service.

Detection Guidance

This vulnerability involves malformed DNS responses causing denial of service. Monitor for unexpected termination of DNS queries or errors in Hickory DNS logs. Check for UDP port exhaustion or abrupt service stops. No specific commands are provided in the context.

Impact Analysis

This vulnerability can cause denial of service by disrupting DNS query processing. If exploited, it may prevent legitimate users from accessing DNS services, leading to interrupted network communications and potential service outages.

Mitigation Strategies

Upgrade Hickory DNS to version 0.26.2 or later to address the issue. Ensure DNS query validation is enforced. Monitor network traffic for malformed packets targeting DNS ports.

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