{"id":"UBUNTU-CVE-2026-123586","details":"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.","modified":"2026-11-10T02:50:14.027145226Z","published":"2026-11-09T00:00:00Z","upstream":["CVE-2026-123586"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-123586"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-123586"},{"type":"REPORT","url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-cx5j-p54p-q756"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/hickory-dns-0.25.0-alpha.3-through-0.25.2-query-amplification-via-cyclic-referrals"}],"affected":[{"package":{"name":"rust-hickory-resolver","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/rust-hickory-resolver?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.0-1"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-hickory-resolver-dev","binary_version":"0.24.0-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123586.json"}},{"package":{"name":"rust-hickory-recursor","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/rust-hickory-recursor?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.1-1","0.25.2-6"],"ecosystem_specific":{"binaries":[{"binary_version":"0.25.2-6","binary_name":"librust-hickory-recursor-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123586.json"}},{"package":{"name":"rust-hickory-resolver","ecosystem":"Ubuntu:26.10","purl":"pkg:deb/ubuntu/rust-hickory-resolver?arch=source&distro=stonking"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.4-5","0.26.1-1"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-hickory-resolver-dev","binary_version":"0.26.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123586.json"}},{"package":{"name":"rust-hickory-recursor","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/rust-hickory-recursor?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.1-1"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-hickory-recursor-dev","binary_version":"0.24.1-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123586.json"}},{"package":{"name":"rust-hickory-resolver","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/rust-hickory-resolver?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.24.4-1","0.24.4-5"],"ecosystem_specific":{"binaries":[{"binary_version":"0.24.4-5","binary_name":"librust-hickory-resolver-dev"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-123586.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"CVSS_V4","score":"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"},{"type":"Ubuntu","score":"medium"}]}