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TI-2026-86732 Aliases CVE-2026-123590GHSA-f6qc-6m8j-6hgc

Improper NSEC and NSEC3 signature validation in Hickory DNS

Priority LOW 27CWE-347Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-347.

Summary

Hickory DNS hickory-net from 0.26.0-beta.1 before 0.26.2 and hickory-proto through 0.26.0-alpha.1 accept NSEC and NSEC3 records for DNSSEC nonexistence proofs when any other record with the same owner name passes signature validation (CWE-347). An attacker who can supply DNS responses can mix validly signed records with bogus same-name NSEC or NSEC3 records in the authority section to forge nonexistence proofs.

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

Description from the CNA

Hickory DNS hickory-net 0.26.0-beta.1 before 0.26.2 and hickory-proto through 0.26.0-alpha.1 accept NSEC and NSEC3 records for DNSSEC nonexistence proofs when any other record with the same owner name passes signature validation. Attackers able to supply DNS responses can mix validly signed records with bogus same-name NSEC or NSEC3 records of different types in the authority section to forge nonexistence proofs.

Why it matters now

EPSS 0.00158 4th percentileScored 2026-11-08
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-dns0.26.0-beta.1 to before 0.26.20.26.2Patch availableCNA
hickory-dnshickory-dnsup to 0.26.0-alpha.1—No fix listedCNA
  • hickory-dns Vendorhickory-dns Affected 0.26.0-beta.1 to before 0.26.2 Fixed in 0.26.2 Patch available CNA
  • hickory-dns Vendorhickory-dns Affected up to 0.26.0-alpha.1 Fixed in — No fix listed CNA

Remediation

Update hickory-net to version 0.26.2. The sources list no fixed version for hickory-proto.

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 LOW 36 LOW

    Other records, highest priority first

    • TI-2026-86748 Resource exhaustion in hickory-dns recursor via glueless NS referralsPriority LOW 38
    • TI-2026-86746 Unbounded retry loop in Hickory DNS resolver enables resource exhaustionPriority LOW 38
    • TI-2026-86730 Denial of service in Hickory DNS recursive resolver via empty poolPriority LOW 38
    Show all 36 records →

Timeline

  1. 2026-11-08 Threatist record created from CVE-2026-123590
  2. 2026-11-08 Alias added: GHSA-f6qc-6m8j-6hgc
  3. 2026-11-09 Priority changed: MEDIUM → LOW

References

Advisory 1

  • TI-2025-18857 DNSSEC validation may accept broken authentication chains CVSS 4.0MEDIUM 5.7
  • TI-2026-63089 hickory-resolver before 0.26.2 DNSSEC Validation Bypass CVSS 4.0HIGH 8.7
  • 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-2026-86746 Unbounded retry loop in Hickory DNS resolver enables resource exhaustion CVSS 4.0HIGH 8.7
See all 40 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences