CVE-2026-123594

Hickory DNS through 0.26.0-alpha.1 DNSSEC NSEC Validation Bypass for Empty Non-Terminals

Published Nov 8, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
Description
Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Hickory-dns
Hickory-dns hickory-dns
Vendors & Products Hickory-dns
Hickory-dns hickory-dns
Type Values Removed Values Added
Description Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain an NSEC validation flaw that returns a secure proof for NXDOMAIN responses when the covering NSEC's Next Domain Name is a strict descendant of the query name, which actually proves the name exists as an empty non-terminal. On-path attackers can flip the unsigned rcode of a genuine signed NODATA response from NOERROR to NXDOMAIN, causing validators to accept forged nonexistence of the name.
Title Hickory DNS through 0.26.0-alpha.1 DNSSEC NSEC Validation Bypass for Empty Non-Terminals
Weaknesses CWE-345
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 9, 2026, 1:51 PM
Reserved
Nov 6, 2026, 12:57 AM
Status
Deferred
Published
Nov 8, 2026, 2:16 AM
Modified
Nov 10, 2026, 10:15 PM