November 14, 2026

CVE Watchtower

CVE-2026-123586hickory-dns hickory-dns Uncontrolled Resource Consumption

NVD

Vulnerability Summary

Hickory DNS 0.25.0-alpha.3 through 0.25.2 contains a query amplification vulnerability in its recursive resolver, which mishandles cyclic sibling name server referrals that lack glue records. Attackers controlling two zones whose name servers reference each other without glue records can make the recursor loop, sending many upstream queries, amplified further by zero-TTL NS records.
Severity Level
HIGH(8.7)
Published Date
Nov 8, 2026
Last Modified
Nov 9, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.34%Probability
Root Weakness (CWE)
CWE-400: Uncontrolled Resource Consumption ↗
The product does not properly control the allocation and maintenance of a limited resource, enabling denial-of-service conditions.
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 >= 0.25.0-alpha.3 and <= 0.25.2
  • hickory-dns hickory-dns < 0.26.2
Patched Versions
  • hickory-dns hickory-dns 0.25.2
  • 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 9, 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