Denial of Service Vulnerability in Hickory-dns by Hickory
CVE-2026-123572

8.7HIGH

Key Information:

Vendor

Hickory-dns

Status
Hickory-dns
Vendor
CVE Published:
8 November 2026

What is CVE-2026-123572?

Hickory-dns versions before 0.26.2 are susceptible to a denial of service due to a flaw in the hickory-proto's SVCB and HTTPS record parser. Attackers can exploit this vulnerability by providing untrusted zone files that contain malformed ALPN values, such as unbalanced quotes, consecutive commas, or invalid escape sequences. This can lead to process crashes, disrupting DNS services.

Affected Version(s)

hickory-dns 0.20.1 < 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-0.20.1-b...
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

kirk-baird
.