{"affected":[{"defaultStatus":"unaffected","ecosystem":"cargo","packageName":"hickory-recursor","product":"hickory-dns","source":"CNA: VulnCheck","vendor":"hickory-dns","versions":[{"lessThanOrEqual":"0.26.0-alpha.1","status":"affected","version":"0.25.0-alpha.3","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"cargo","packageName":"hickory-resolver","product":"hickory-dns","source":"CNA: VulnCheck","vendor":"hickory-dns","versions":[{"lessThan":"0.26.2","status":"affected","version":"0.26.0","versionType":"semver"},{"status":"unaffected","version":"0.26.2","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"cargo","packageName":"hickory-proto","product":"hickory-dns","source":"CNA: VulnCheck","vendor":"hickory-dns","versions":[{"lessThan":"0.26.2","status":"affected","version":"0.26.0","versionType":"semver"},{"status":"unaffected","version":"0.26.2","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"cargo","packageName":"hickory-server","product":"hickory-dns","source":"CNA: VulnCheck","vendor":"hickory-dns","versions":[{"lessThan":"0.26.2","status":"affected","version":"0.25.0-alpha.1","versionType":"semver"},{"status":"unaffected","version":"0.26.2","versionType":"semver"}]}],"cveId":"CVE-2026-123603","cwes":["CWE-284"],"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.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":6.9,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","version":"4.0"},{"score":6.5,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}],"modifiedAt":1794101910679,"publishedAt":1794101910679,"references":[{"source":"CNA: VulnCheck","tags":["vendor-advisory"],"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-4jwp-xjwm-333g"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/hickory-dns-missing-ipv4-mapped-ipv6-canonicalization-access-control-bypass"}],"remediation":[],"revision":"71dad7997137a2c27a088e3281c25c6dbe7cf6baae2baed5379d2a8b17a0d985","sources":[{"modifiedAt":1794101910679,"name":"CNA: VulnCheck","retrievedAt":1794103841145,"url":"https://www.cve.org/CVERecord?id=CVE-2026-123603"}],"ssvc":null,"status":"published","title":"Hickory DNS Missing IPv4-Mapped IPv6 Canonicalization Access Control Bypass","updatedAt":1794103841145}