Resource Exhaustion Vulnerability in Hickory DNS by Hickory
CVE-2026-123577

8.7HIGH

Key Information:

Vendor

Hickory-dns

Status
Hickory-dns
Vendor
CVE Published:
8 November 2026

What is CVE-2026-123577?

Hickory DNS presents a significant resource exhaustion flaw in versions prior to 0.26.2, which permits remote attackers to exploit the system by sending excessively large DNS over HTTP (DoH) request bodies. This can lead to extensive server memory consumption and ultimately result in denial of service, affecting the availability of the DNS service. Remote attackers can utilize HTTP/2 or HTTP/3 protocols to send these unbounded request bodies, highlighting the need for immediate attention and remediation.

Affected Version(s)

hickory-dns 0.24.0 < 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-0.24.0-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

BeaCox
.