CVE-2026-123607 PUBLISHED

Hickory DNS NSEC3 Closest-Encloser Proof Unbounded Loop Denial of Service

Assigner: VulnCheck
Reserved: 06.11.2026 Published: 08.11.2026 Updated: 08.11.2026

Hickory DNS hickory-proto 0.25.0-alpha.3 through 0.25.2 and hickory-net before 0.26.1 contain an unbounded loop vulnerability in DnssecDnsHandle NSEC3 closest-encloser proof validation when the SOA owner is not an ancestor of the QNAME. Upstream attackers can return NoData or NXDomain responses with a cross-zone SOA record to panic debug builds or exhaust memory in release builds.

CVSS Vector: 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
CVSS Score: 8.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	hickory-dns
Product	hickory-dns
Versions	Default: unaffected affected from 0.25.0-alpha.3 to 0.25.2 (incl.)

Vendor	hickory-dns
Product	hickory-dns
Versions	Default: unaffected affected from 0.26.0-alpha.1 to 0.26.1 (excl.) Version 0.26.1 is unaffected

References

Problem Types

Loop with Unreachable Exit Condition ('Infinite Loop') CWE