November 14, 2026

CVE Watchtower

CVE-2026-123604hickory-dns hickory-dns Loop with Unreachable Exit Condition (Infinite Loop)

NVD

Vulnerability Summary

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.
Severity Level
HIGH(8.7)
Published Date
Nov 8, 2026
Last Modified
Nov 12, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.34%Probability
Root Weakness (CWE)
CWE-835: Loop with Unreachable Exit Condition (Infinite Loop) ↗
The product contains an iteration or loop with an exit condition that cannot be reached.
CVSS v4.0 Base Metrics — Score 8.7 (HIGH)
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
Attack VectorNetwork
Attack ComplexityLow
Attack RequirementsNone
Privileges RequiredNone
User InteractionNone
Confidentiality (Vulnerable System)None
Integrity (Vulnerable System)None
Availability (Vulnerable System)High
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None
Show CVSS v3.x metrics (score 7.5)
CVSS v3.1 Base Metrics — Score 7.5 (HIGH)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh

Affected & Patched Versions

Affected Versions
  • hickory-dns hickory-dns >= 0.26.0-beta.1 and < 0.26.2
Patched Versions
  • hickory-dns hickory-dns 0.26.2

What to do

Plan remediation soon. No exploitation is confirmed yet, but the severity is high.

  1. Check whether you run hickory-dns hickory-dns and which version.
  2. Update to a patched version listed above, then confirm the new version.

Timeline

  • Nov 8, 2026Published
  • Nov 12, 2026Record last modified

Score, severity and exploitation changes are tracked from the day Watchtower started logging them.

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External References

Data last checked: Nov 14, 2026 02:13 UTC