Denial of Service Vulnerability in Hickory DNS by Hickory
CVE-2026-123608

8.7HIGH

Key Information:

Vendor

Hickory-dns

Status
Hickory-dns
Vendor
CVE Published:
8 November 2026

What is CVE-2026-123608?

The hickory-proto version of Hickory DNS contains a denial of service vulnerability due to inefficient name compression in the BinEncoder component. This weakness allows remote attackers to exploit the system by sending specially crafted DNS messages that trigger excessive CPU consumption. The exploit is facilitated through quadratic-time name compression, where an attacker can introduce numerous records that result in repeated linear scans during the encoding process, leading to significant CPU resource exhaustion.

Affected Version(s)

hickory-dns 0.3.1 < 0.26.1

hickory-dns 0.26.1

References

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

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

qifan-sailboat
.