{"id":"CVE-2026-123588","title":"Hickory DNS Recursive Resolver Denial of Service via Cached Empty Connection Pool","summary":"The recursive resolver in Hickory DNS (all versions of the hickory-recursor crate, and hickory-resolver 0.26.0 before 0.26.2) caches an empty connection pool when it follows a referral with no glue records and all queries for the name se…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-754"],"vendor":"hickory-dns","product":"hickory-dns","affected":["hickory-dns <= 0.26.0-alpha.1","hickory-dns >= 0.26.0 < 0.26.2"],"published":"2026-11-08","updated":"2026-11-08","sourceUpdated":"2026-11-08T01:38:20.288Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-123588","references":[{"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-9px7-7m25-f6q2","label":"GitHub Security Advisory (GHSA-9px7-7m25-f6q2)"},{"url":"https://www.vulncheck.com/advisories/hickory-dns-recursive-resolver-denial-of-service-via-cached-empty-connection-pool","label":"VulnCheck Advisory: Hickory DNS Recursive Resolver Denial of Service via Cached Empty Connection Pool"}],"tags":["cve.org"],"ingestedAt":"2026-11-08T02:43:18.650Z","slug":"CVE-2026-123588","body":"## Overview\n\nThe recursive resolver in Hickory DNS (all versions of the hickory-recursor crate, and hickory-resolver 0.26.0 before 0.26.2) caches an empty connection pool when it follows a referral with no glue records and all queries for the name servers' IP addresses fail. An attacker able to spoof DNS responses can make these lookups fail, causing all subsequent queries for the affected zone to fail until the cache entry expires or is evicted.\n\n## Affected\n\n- `hickory-dns <= 0.26.0-alpha.1`\n- `hickory-dns >= 0.26.0 < 0.26.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}