Logic Bug in Hickory DNS Exposes Vulnerability in DNSSEC Validation
CVE-2026-123597

6.3MEDIUM

Key Information:

Vendor

Hickory-dns

Status
Hickory-dns
Vendor
CVE Published:
8 November 2026

What is CVE-2026-123597?

Hickory DNS versions hickory-proto 0.25.0-alpha.1 through 0.26.0-alpha.1 and hickory-net prior to 0.26.2 contain a logic bug in the DnssecDnsHandle's DS-fetch process. This bug results in transient DS lookup errors being incorrectly cached as Bogus DNSSEC validation results. Consequently, if an attacker prompts a SERVFAIL, REFUSED, or a timeout response during a child-zone DS sub-query, the DNS validator will erroneously return SERVFAIL for all names within that affected zone until the cached entry's TTL expires, leading to potential service disruption and security issues.

Affected Version(s)

hickory-dns 0.25.0-alpha.1 <= 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-dnssec-v...
third-party-advisory

CVSS V4

Score:
6.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
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
.