Is CVE-2026-123573 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-123573 being exploited in the wild.

How severe is CVE-2026-123573?

High severity, with a CVSS score of 7.5, published 8 November 2026.

Which products and versions are affected?

Hickory-Dns Hickory-Proto 0.20.1 through 0.26.1.

Is there a fix for CVE-2026-123573?

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

How is CVE-2026-123573 attacked?

It is attacked over the network.

Am I affected by CVE-2026-123573?

Check whether you run Hickory-Dns Hickory-Proto 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-2026-123573: hickory-dns denial of service in SVCB and HTTPS record parser

CVE-2026-123573 · Severity: high · CVSS 7.5 · Published 2026-11-08

hickory-dns is a DNS protocol library used to parse DNS zone files and records. A flaw in parsing SVCB and HTTPS DNS record types causes the parser to crash (panic) when encountering malformed service parameter values containing only quotes. An attacker supplying a malicious zone file can trigger a denial of service, disrupting any application that processes untrusted DNS zone data.

Technologies: Hickory-Dns Hickory-Proto. Vendors: Hickory-Dns.

Quick answers

Is CVE-2026-123573 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-123573 being exploited in the wild.
How severe is CVE-2026-123573?: High severity, with a CVSS score of 7.5, published 8 November 2026.
Which products and versions are affected?: Hickory-Dns Hickory-Proto 0.20.1 through 0.26.1.
Is there a fix for CVE-2026-123573?: Yes: fixed in hickory-proto 0.26.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-123573 attacked?: It is attacked over the network.
Am I affected by CVE-2026-123573?: Check whether you run Hickory-Dns Hickory-Proto 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: hickory-proto 0.26.2

Technical details

The hickory-proto component's presentation format parser for SVCB (RR type 64) and HTTPS (RR type 65) records fails to validate service parameter values and panics when a quote character appears in place of a valid parameter value. Exploitation requires the ability to provide untrusted zone file input to a system running the vulnerable versions. This is a denial of service vulnerability with no authentication or user interaction required.

Affected products

hickory-dns hickory-proto 0.20.1 through 0.26.1

Timeline

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

References

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