{"affected":[{"defaultStatus":"unaffected","ecosystem":"cargo","packageName":"hickory-proto","product":"hickory-dns","source":"CNA: VulnCheck","vendor":"hickory-dns","versions":[{"lessThanOrEqual":"0.26.0-alpha.1","status":"affected","version":"0","versionType":"semver"}]},{"defaultStatus":"unaffected","ecosystem":"cargo","packageName":"hickory-net","product":"hickory-dns","source":"CNA: VulnCheck","vendor":"hickory-dns","versions":[{"lessThan":"0.26.2","status":"affected","version":"0.26.0-beta.1","versionType":"semver"},{"status":"unaffected","version":"0.26.2","versionType":"semver"}]}],"cveId":"CVE-2026-123596","cwes":["CWE-345"],"description":"Hickory DNS hickory-proto through 0.26.0-alpha.1 and hickory-net 0.26.0-beta.1 before 0.26.2 contain a DNSSEC validation flaw in the validating recursor's NSEC handler that accepts parent-side ancestor-delegation NSEC records as proof of nonexistence for names below the zone cut. An on-path attacker, rogue parent nameserver, or attacker winning a port and TXID race can deliver one forged NXDOMAIN response built from genuinely signed parent NSEC records, causing authenticated denial of existing child-zone names cached for the negative TTL.","epss":null,"exploits":[],"kev":null,"metrics":[{"score":8.7,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"},{"score":8.8,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}],"modifiedAt":1794101905747,"publishedAt":1794101905747,"references":[{"source":"CNA: VulnCheck","tags":["vendor-advisory"],"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3r6v-f3jh-vvqm"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-validation-bypass-via-ancestor-delegation-nsec"}],"remediation":[],"revision":"a816a87ac0cecfcf804485faf14708bb18b1dd9527d1c37a0cd8b82dc5ff9075","sources":[{"modifiedAt":1794101905747,"name":"CNA: VulnCheck","retrievedAt":1794103833229,"url":"https://www.cve.org/CVERecord?id=CVE-2026-123596"}],"ssvc":null,"status":"published","title":"Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC","updatedAt":1794103833229}