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Ghost domain attack in Hickory DNS recursor via cached NS records

Priority MEDIUM 51CWE-672Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · High · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

All versions of hickory-recursor and hickory-resolver from 0.26.0-beta.1 before 0.26.2 (recursor feature) reuse child-side apex NS records cached from zone NS queries for iterative resolution (CWE-672). A remote attacker without privileges repeatedly queries a zone's NS records to keep the stale set cached indefinitely. Name servers whose delegation the parent revoked keep answering for the zone.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

Description from the CNA

The Hickory DNS recursor in all versions of hickory-recursor and in hickory-resolver 0.26.0-beta.1 before 0.26.2 (recursor feature) is vulnerable to ghost domain names attacks because it reuses child-side apex NS RRsets cached from zone NS queries for iterative resolution. By repeatedly querying a zone's NS records, an attacker keeps the stale RRset cached indefinitely, letting name servers whose delegation the parent revoked keep answering for the zone.

Why it matters now

Fix Fixed hickory-dns (hickory-dns): 0.26.2

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
hickory-dnshickory-dnsup to 0.26.0-alpha.1—No fix listedCNA
hickory-dnshickory-dns0.26.0-beta.1 to before 0.26.20.26.2Patch availableCNA
  • hickory-dns Vendorhickory-dns Affected up to 0.26.0-alpha.1 Fixed in — No fix listed CNA
  • hickory-dns Vendorhickory-dns Affected 0.26.0-beta.1 to before 0.26.2 Fixed in 0.26.2 Patch available CNA

Remediation

Upgrade hickory-resolver to 0.26.2. The sources list no fixed version for hickory-recursor.

Written with Claude Haiku 5.5 from the sources below · 2026-11-08

  • Fix · CNA hickory-dns (hickory-dns) Fixed in 0.26.2

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    hickory-dns 0.26.2

    36 records Highest priority Priority MEDIUM 36 MEDIUM

    Other records, highest priority first

    • TI-2026-86729 DNSSEC nonexistence forgery in Hickory DNS via wraparound NSECPriority MEDIUM 54
    • TI-2026-86748 Resource exhaustion in hickory-dns recursor via glueless NS referralsPriority MEDIUM 53
    • TI-2026-86747 DNSSEC validation bypass in Hickory DNS via RRSIG signer namePriority MEDIUM 53

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-123602
  2. 2026-11-08 Alias added: GHSA-4vjf-x5x5-8f5h

References

  • TI-2025-18857 DNSSEC validation may accept broken authentication chains CVSS 4.0MEDIUM 5.7
  • TI-2026-86729 DNSSEC nonexistence forgery in Hickory DNS via wraparound NSEC CVSS 4.0HIGH 8.9
  • TI-2026-86750 CPU exhaustion in Hickory DNS hickory-proto via BinEncoder name compression CVSS 4.0HIGH 8.7
  • TI-2026-86749 Hickory DNS NSEC3 validation loop enables denial of service CVSS 4.0HIGH 8.7
  • TI-2026-86748 Resource exhaustion in hickory-dns recursor via glueless NS referrals CVSS 4.0HIGH 8.7
  • TI-2026-86747 DNSSEC validation bypass in Hickory DNS via RRSIG signer name CVSS 4.0HIGH 8.7
See all 40 →

Sources