CVE-2026-123573: Input Validation Flaw (CVSS 7.5)

Description

hickory-dns from 0.20.1 before 0.26.2 contains a denial of service vulnerability in the hickory-proto SVCB and HTTPS record presentation format parser. Attackers can supply untrusted zone files where only a single or double quote replaces a service parameter value, triggering a panic that crashes the parsing process.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0034

Probability of exploitation

0.28%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-20 Improper Input Validation

References

Other References

https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-wgfr-mphw-j5g4 https://www.vulncheck.com/advisories/hickory-dns-from-0.20.1-before-0.26.2-panic-in-svcb-https-zone-file-parser

Frequently Asked Questions

What is CVE-2026-123573? +

hickory-dns from 0.20.1 before 0.26.2 contains a denial of service vulnerability in the hickory-proto SVCB and HTTPS record presentation format parser. Attackers can supply untrusted zone files where only a single or double quote replaces a service parameter value, triggering a panic that crashes the parsing process. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-123573? +

CVE-2026-123573 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0034, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-123573? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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