{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-123603","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-11-06T01:00:16.506Z","datePublished":"2026-11-08T01:38:30.679Z","dateUpdated":"2026-11-13T03:10:51.830Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-11-08T01:38:30.679Z"},"datePublic":"2026-09-03T00:00:00.000Z","title":"Hickory DNS Missing IPv4-Mapped IPv6 Canonicalization Access Control Bypass","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"Improper Access Control","cweId":"CWE-284","type":"CWE"}]}],"affected":[{"vendor":"hickory-dns","product":"hickory-dns","defaultStatus":"unaffected","packageURL":"pkg:cargo/hickory-recursor","versions":[{"version":"0.25.0-alpha.3","status":"affected","versionType":"semver","lessThanOrEqual":"0.26.0-alpha.1"}]},{"vendor":"hickory-dns","product":"hickory-dns","defaultStatus":"unaffected","packageURL":"pkg:cargo/hickory-resolver","versions":[{"version":"0.26.0","status":"affected","versionType":"semver","lessThan":"0.26.2"},{"version":"0.26.2","status":"unaffected","versionType":"semver"}]},{"vendor":"hickory-dns","product":"hickory-dns","defaultStatus":"unaffected","packageURL":"pkg:cargo/hickory-proto","versions":[{"version":"0.26.0","status":"affected","versionType":"semver","lessThan":"0.26.2"},{"version":"0.26.2","status":"unaffected","versionType":"semver"}]},{"vendor":"hickory-dns","product":"hickory-dns","defaultStatus":"unaffected","packageURL":"pkg:cargo/hickory-server","versions":[{"version":"0.25.0-alpha.1","status":"affected","versionType":"semver","lessThan":"0.26.2"},{"version":"0.26.2","status":"unaffected","versionType":"semver"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":6.9,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS"},{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM"},"format":"CVSS"}],"references":[{"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-4jwp-xjwm-333g","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-4jwp-xjwm-333g)"},{"name":"VulnCheck Advisory: Hickory DNS Missing IPv4-Mapped IPv6 Canonicalization Access Control Bypass","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/hickory-dns-missing-ipv4-mapped-ipv6-canonicalization-access-control-bypass"}],"credits":[{"lang":"en","value":"qifan-sailboat","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-11-13T03:10:41.977245Z","id":"CVE-2026-123603","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-11-13T03:10:51.830Z"}}]}}