CVE-2026-123596hickory-dns hickory-dns Insufficient Verification of Data Authenticity
NVD
Vulnerability Summary
Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC handler that accepts parent-side ancestor-delegation NSEC records as proof of nonexistence for names below the zone cut. An on-path attacker, rogue parent nameserver, or attacker winning a port and TXID race can deliver one forged NXDOMAIN response built from genuinely signed parent NSEC records, causing authenticated denial of existing child-zone names cached for the negative TTL.
CVSS v4.0 Base Metrics — Score 8.7 (HIGH)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NAttack VectorNetwork
Attack ComplexityLow
Attack RequirementsNone
Privileges RequiredLow
User InteractionNone
Confidentiality (Vulnerable System)High
Integrity (Vulnerable System)High
Availability (Vulnerable System)High
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None
Show CVSS v3.x metrics (score 8.8)
CVSS v3.1 Base Metrics — Score 8.8 (HIGH)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HAttack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
Affected & Patched Versions
- hickory-dns hickory-dns <= 0.26.0-alpha.1
- hickory-dns hickory-dns >= 0.26.0-beta.1 and < 0.26.2
- hickory-dns hickory-dns 0.26.0-alpha.1
- hickory-dns hickory-dns 0.26.2
What to do
Plan remediation soon. No exploitation is confirmed yet, but the severity is high.
- Check whether you run hickory-dns hickory-dns and which version.
- 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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Data last checked: Nov 14, 2026 02:13 UTC