Is CVE-2026-123589 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-123589 being exploited in the wild.

How severe is CVE-2026-123589?

Medium severity, with a CVSS score of 5.3, published 8 November 2026.

Which products and versions are affected?

Hickory-Dns Hickory-Server <0.26.2.

Is there a fix for CVE-2026-123589?

Yes: fixed in 0.26.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-123589 attacked?

It is attacked over the network.

Am I affected by CVE-2026-123589?

Check whether you run Hickory-Dns Hickory-Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-123589: hickory-dns DoQ server request read timeout bypass

Q: Is there a fix for CVE-2026-123589?

Yes: fixed in 0.26.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-123589 attacked?

It is attacked over the network.

Q: Am I affected by CVE-2026-123589?

Check whether you run Hickory-Dns Hickory-Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-123589 · Severity: medium · CVSS 5.3 · Published 2026-11-08

hickory-dns is a DNS server library that supports DNS-over-QUIC (DoQ), a protocol for secure DNS queries. The server fails to enforce timeouts when reading incoming DNS requests over QUIC, allowing an attacker to open a connection and hold it open indefinitely without sending a complete message. This causes the server to consume resources exhaustively, resulting in a denial of service that prevents legitimate DNS queries from being answered.

Vendors: Hickory-Dns.

Quick answers

Is CVE-2026-123589 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-123589 being exploited in the wild.
How severe is CVE-2026-123589?: Medium severity, with a CVSS score of 5.3, published 8 November 2026.
Which products and versions are affected?: Hickory-Dns Hickory-Server <0.26.2.
Is there a fix for CVE-2026-123589?: Yes: fixed in 0.26.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-123589 attacked?: It is attacked over the network.
Am I affected by CVE-2026-123589?: Check whether you run Hickory-Dns Hickory-Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 0.26.2

Technical details

The DoQ server implementation in hickory-dns before 0.26.2 does not apply any timeout constraint to the stream read operation for incoming request messages, bypassing the application's configured timeouts. A remote unauthenticated client can exploit this via the network by opening a QUIC connection, starting a request stream, and holding it open indefinitely. This causes server resource exhaustion and denial of service; a fix is available in version 0.26.2 and later.

Affected products

hickory-dns hickory-server <0.26.2

Timeline

2026-09-03: disclosed
2026-11-08: advisory

References

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