Vulnerability in Hickory-Dns
CVE-2026-123595
Hickory DNS hickory-proto 0.25 through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC3 handler, which matches the closest encloser by hash alone without checking the type bitmap and so accepts parent-side ancestor-delegation NSEC3 records as proof of nonexistence. An attacker who delivers one response built from genuinely signed parent NSEC3 records can cause NXDOMAIN or NODATA to be cached with AD=1, denying resolution of existing names at and below the zone cut.
Published .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
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-624w-vvww-xvpw) (vendor-advisory)
- VulnCheck Advisory: Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC3 (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123595?
- CVE-2026-123595 is a high-severity vulnerability in Hickory-Dns, classified under Insufficient Verification of Data Authenticity. CVSS score: 8.8/10. Published 2026-11-08.
- How severe is CVE-2026-123595?
- High severity. CVSS v3 base score is 8.8 out of 10.