Vulnerability in Hickory-Dns
CVE-2026-123591
Hickory DNS hickory-net 0.26.0-beta.1 before 0.26.2 and hickory-proto through 0.26.0-alpha.1 fail to verify, per RFC 6840 §4.4, that an NSEC or NSEC3 record denying a DS RRset also proves the delegation's NS record exists. Attackers can reuse child-side NSEC or NSEC3 records to fake an insecure delegation and forge child-zone records.
Published .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-7php-9j59-g3ch) (vendor-advisory)
- VulnCheck Advisory: Hickory DNS 0.26.0-beta.1 before 0.26.2 DNSSEC Validation Bypass via Missing RFC 6840 Checks (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123591?
- CVE-2026-123591 is a medium-severity vulnerability in Hickory-Dns, classified under Insufficient Verification of Data Authenticity. CVSS score: 5.9/10. Published 2026-11-08.
- How severe is CVE-2026-123591?
- Medium severity. CVSS v3 base score is 5.9 out of 10.