Bug 2568790 (CVE-2026-123586) - CVE-2026-123586 hickory-resolver: hickory-resolver: Denial of Service via cyclic DNS referrals
Summary: CVE-2026-123586 hickory-resolver: hickory-resolver: Denial of Service via cyc...
Keywords:
Status: NEW
Alias: CVE-2026-123586
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-11-08 02:06 UTC by OSIDB Bzimport
Modified: 2026-11-08 02:45 UTC (History)
15 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-11-08 02:06:15 UTC 
Hickory DNS 0.25.0-alpha.3 through 0.25.2 contains a query amplification vulnerability in its recursive resolver, which mishandles cyclic sibling name server referrals that lack glue records. Attackers controlling two zones whose name servers reference each other without glue records can make the recursor loop, sending many upstream queries, amplified further by zero-TTL NS records.
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