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.
History

Mon, 09 Nov 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Hickory-dns
Hickory-dns hickory-dns
Vendors & Products Hickory-dns
Hickory-dns hickory-dns

Sun, 08 Nov 2026 01:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC3
Weaknesses CWE-345
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-11-08T01:38:25.078Z

Updated: 2026-11-08T01:38:25.078Z

Reserved: 2026-11-06T01:00:16.505Z

Link: CVE-2026-123595

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-08T02:16:53.863

Modified: 2026-11-08T02:16:53.863

Link: CVE-2026-123595

cve-icon Redhat

No data.