{"id":"CVE-2026-123596","aliases":["RUSTSEC-2026-0530","GHSA-3r6v-f3jh-vvqm","RUSTSEC-2026-0539"],"title":"Hickory DNS through 0.26.0-alpha.1 DNSSEC Validation Bypass via Ancestor-Delegation NSEC","titleSource":"VulnCheck","descriptionSource":"OSV","description":"Up to 0.26.0-alpha.1, hickory-proto's DNSSEC validation accepted the NSEC record that a parent zone signs at a delegation as proof that names below the zone cut, or other types at the cut, do not exist. Such a record only proves that no DS record exists there (RFC 6840 section 4.1). Someone who can answer or modify DNS responses could replay the parent's genuine signed records to get a denial for an existing name in the child zone accepted as secure.\n\nFrom 0.26.0-beta.1 the DNSSEC validation code lives in the hickory-net crate, where this was fixed in hickory-net 0.26.2. No hickory-proto release contains a fix. Users of DNSSEC validation in older hickory-proto releases (directly or through hickory-resolver or hickory-recursor) should move to the 0.26.2 or later releases, which validate through hickory-net.","severity":"high","score":8.8,"published":"2026-09-03T12:00:00.000Z","modified":"2026-11-13T12:55:36.653Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"crates.io","name":"hickory-proto","sources":[{"name":"OSV · RUSTSEC-2026-0530","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0530"}],"ranges":[{"events":[{"introduced":"0.0.0-0"},{"fixed":"0.26.0-beta.1"}],"type":"SEMVER"}],"versions":[],"fixed":["0.26.0-beta.1"]},{"ecosystem":"crates.io","name":"hickory-net","sources":[{"name":"OSV · RUSTSEC-2026-0539","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0539"}],"ranges":[{"events":[{"introduced":"0.0.0-0"},{"fixed":"0.26.2"}],"type":"SEMVER"}],"versions":[],"fixed":["0.26.2"]}],"sourceAffected":[],"references":["https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3r6v-f3jh-vvqm","https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-validation-bypass-via-ancestor-delegation-nsec","https://crates.io/crates/hickory-proto","https://rustsec.org/advisories/RUSTSEC-2026-0530.html","https://github.com/hickory-dns/hickory-dns/commit/2e3c829ea45000b1c409a64a03bd422618372471","https://crates.io/crates/hickory-net","https://rustsec.org/advisories/RUSTSEC-2026-0539.html"],"sources":[{"name":"CVE","id":"CVE-2026-123596","modified":"2026-11-12T13:30:41.852Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-123596"},{"name":"OSV","id":"RUSTSEC-2026-0530","modified":"2026-11-13T12:55:36.653610929Z","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0530"},{"name":"OSV","id":"RUSTSEC-2026-0539","modified":"2026-11-13T12:55:36.653610929Z","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0539"}],"assessments":[{"source":"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","score":8.7},{"source":"VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8}],"cve":{"records":[{"id":"CVE-2026-123596","source":"VulnCheck","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-11-06T01:00:16.505Z","published":"2026-11-08T01:38:25.747Z","modified":"2026-11-12T13:30:41.852Z"}],"publishers":[{"name":"VulnCheck","role":"CNA","organizationId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","modified":"2026-11-08T01:38:25.747Z"},{"name":"CISA-ADP","role":"ADP","organizationId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","modified":"2026-11-12T13:30:41.852Z"}],"references":[{"url":"https://github.com/hickory-dns/hickory-dns/security/advisories/GHSA-3r6v-f3jh-vvqm","tags":["vendor-advisory"],"source":"VulnCheck"},{"url":"https://www.vulncheck.com/advisories/hickory-dns-through-0.26.0-alpha.1-dnssec-validation-bypass-via-ancestor-delegation-nsec","tags":["third-party-advisory"],"source":"VulnCheck"}],"weaknesses":[{"id":"CWE-345","description":"Insufficient Verification of Data Authenticity","source":"VulnCheck"}],"applicability":[],"prioritization":[{"source":"CISA-ADP","type":"SSVC","role":"CISA Coordinator","timestamp":"2026-11-12T13:29:11.074677Z","decisions":[{"name":"Exploitation","value":"none"},{"name":"Automatable","value":"no"},{"name":"Technical Impact","value":"total"}]}]},"products":[{"vendor":"hickory-dns","name":"hickory-dns","platforms":[],"versions":[{"version":"0","status":"affected","lessThanOrEqual":"0.26.0-alpha.1","versionType":"semver"}],"defaultStatus":"unaffected","packageURL":"pkg:cargo/hickory-proto","packageIdentity":{"ecosystem":"crates.io","name":"hickory-proto"},"cpes":[],"source":"VulnCheck","url":"https://www.cve.org/CVERecord?id=CVE-2026-123596"},{"vendor":"hickory-dns","name":"hickory-dns","platforms":[],"versions":[{"version":"0.26.0-beta.1","status":"affected","lessThan":"0.26.2","versionType":"semver"},{"version":"0.26.2","status":"unaffected","versionType":"semver"}],"defaultStatus":"unaffected","packageURL":"pkg:cargo/hickory-net","packageIdentity":{"ecosystem":"crates.io","name":"hickory-net"},"cpes":[],"source":"VulnCheck","url":"https://www.cve.org/CVERecord?id=CVE-2026-123596"}],"remediation":[],"observedAt":"2026-11-13T19:08:05.839Z","kev":{"status":"not-listed","checkedAt":"2026-11-15T01:25:32.844Z"},"coverage":[{"source":"NVD","status":"no-result","checkedAt":"2026-11-08T02:15:33.594Z","attemptedAt":"2026-11-08T02:15:33.594Z"},{"source":"GHSA","status":"no-result","checkedAt":"2026-11-08T02:15:33.593Z","attemptedAt":"2026-11-08T02:15:33.593Z"},{"source":"EUVD","status":"no-result","checkedAt":"2026-11-08T02:15:34.099Z","attemptedAt":"2026-11-08T02:15:34.099Z"},{"source":"EPSS","status":"no-result","checkedAt":"2026-11-08T02:15:33.624Z","attemptedAt":"2026-11-08T02:15:33.624Z"}],"evidence":[],"aiSummary":{"text":"Hickory DNS through 0.26.0-alpha.1 has a DNSSEC validation bypass via ancestor-delegation NSEC, allowing an attacker who can modify DNS responses to replay genuine signed records and get a denial for an existing name accepted as secure. The weakness is due to insufficient verification of data authenticity. Affected versions are hickory-proto up to 0.26.0-alpha.1 and hickory-net before 0.26.2.","model":"@cf/meta/llama-3.3-70b-instruct-fp8-fast","generatedAt":"2026-11-14T03:16:15.748Z","sources":[{"name":"CVE","url":"https://www.cve.org/CVERecord?id=CVE-2026-123596"},{"name":"OSV","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0530"},{"name":"OSV","url":"https://osv.dev/vulnerability/RUSTSEC-2026-0539"}]}}