Improper input validation in Hickory-Dns
CVE-2026-123574
The zone file parser in the hickory-proto crate of Hickory DNS 0.24.0 before 0.26.2 panics when a single token in a zone file is 4096 bytes or longer. Attackers who can supply untrusted zone files to an application using the parser can trigger the panic to cause a denial of service.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.003 (28.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
Weakness classification (CWE)
References
- github.com/hickory-dns/hickory-dns/security/advisories/GHSA-4rph-pmrw-mwpw (vendor-advisory)
- www.vulncheck.com/advisories/hickory-dns-0.24.0-before-0.26.2-denial-of-service… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123574?
- CVE-2026-123574 is a high-severity vulnerability in Hickory-Dns, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-11-08.
- How severe is CVE-2026-123574?
- High severity. CVSS v3 base score is 7.5 out of 10.