{"id":"CVE-2026-123603","published":"2026-11-08T02:16:55.117","lastModified":"2026-11-10T22:15:59.797","description":"hickory-proto and hickory-resolver 0.26.0 before 0.26.2, hickory-server 0.25.0-alpha.1 before 0.26.2, and hickory-recursor 0.25.0-alpha.3 through 0.26.0-alpha.1 fail to canonicalize IPv4-mapped IPv6 addresses when checking deny_answers, deny_server, or AccessControlSet rules. Attackers can use IPv4-mapped addresses to evade answer filtering, trigger queries to denied nameservers, or reach hickory-server library deployments on dual-stack IPv6 sockets from denied clients.","cvssScore":6.5,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","cwes":["CWE-284"],"vendors":[],"products":[],"references":[{"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-4jwp-xjwm-333g","tags":[]},{"url":"https://www.vulncheck.com/advisories/hickory-dns-missing-ipv4-mapped-ipv6-canonicalization-access-control-bypass","tags":[]}],"exploitRefs":[{"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-4jwp-xjwm-333g","tags":[]}],"hasPoc":true,"ai":null}