NSEC Validation Flaw in Hickory DNS Products
CVE-2026-123594

6.3MEDIUM

Key Information:

Vendor

Hickory-dns

Status
Hickory-dns
Vendor
CVE Published:
8 November 2026

What is CVE-2026-123594?

The Hickory DNS software, specifically versions hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2, contains a significant flaw in its NSEC validation. This vulnerability allows an on-path attacker to manipulate the DNS response codes, changing a legitimate signed NODATA response from NOERROR to NXDOMAIN. This deception could mislead DNS validators into accepting a forged claim of nonexistence for a queried name, creating potential risks for domain resolution and security.

Affected Version(s)

hickory-dns 0 <= 0.26.0-alpha.1

hickory-dns 0.26.0-beta.1 < 0.26.2

hickory-dns 0.26.2

References

https://github.com/hickory-dns/hickory-dns/security/advis...
vendor-advisory
https://www.vulncheck.com/advisories/hickory-dns-through-...
third-party-advisory

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
Physical
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

qifan-sailboat
.