CVE-2026-123584

MEDIUMCVSS 5.9/10

Last modified

CVE-2026-123584 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. 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..

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
hickory-dnshickory-dns>= 0.26.0, < 0.26.2

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-123584?
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.
How severe is CVE-2026-123584?
CVE-2026-123584 has a CVSS score of 5.9/10 (MEDIUM severity).
How do I fix CVE-2026-123584?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST