Bug 2568778 (CVE-2026-123602)

Summary: CVE-2026-123602 hickory-recursor: hickory-resolver: Hickory DNS: DNS cache poisoning via child-side name server record reuse
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerability-draftAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Hickory DNS. A remote attacker can exploit this vulnerability to carry out a Domain Name System (DNS) cache poisoning attack, commonly referred to as a ghost domain attack, by repeatedly querying a domain's Name Server (NS) records. Because the recursor reuses cached child-side name server records during resolution, stale records remain cached indefinitely, allowing name servers whose authority was revoked by the parent domain to continue providing unauthorized responses.
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Description OSIDB Bzimport 2026-11-08 02:06:15 UTC
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.