Hickory DNS hickory-resolver 0.26.0-beta.1 before 0.26.2 contains an unbounded retry loop in NameServerPool::try_send, which re-queues truncated (TC) responses without checking the answering transport or counting iterations. A malicious authoritative server returning TC=1 on every transport keeps the resolver spinning on a persistent TCP connection until the 5-second request deadline expires, causing resource exhaustion.
History

Mon, 09 Nov 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Hickory-dns
Hickory-dns hickory-dns
Vendors & Products Hickory-dns
Hickory-dns hickory-dns

Sun, 08 Nov 2026 01:45:00 +0000

Type Values Removed Values Added
Description Hickory DNS hickory-resolver 0.26.0-beta.1 before 0.26.2 contains an unbounded retry loop in NameServerPool::try_send, which re-queues truncated (TC) responses without checking the answering transport or counting iterations. A malicious authoritative server returning TC=1 on every transport keeps the resolver spinning on a persistent TCP connection until the 5-second request deadline expires, causing resource exhaustion.
Title Hickory DNS 0.26.0-beta.1 before 0.26.2 Resource Exhaustion DoS via NameServerPool::try_send TC-Retry Loop
Weaknesses CWE-835
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-11-08T01:38:31.351Z

Updated: 2026-11-12T13:34:44.888Z

Reserved: 2026-11-06T01:00:16.506Z

Link: CVE-2026-123604

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-08T02:16:55.273

Modified: 2026-11-12T14:17:26.477

Link: CVE-2026-123604

cve-icon Redhat

No data.