{"id":"CVE-2026-13321","state":"PUBLISHED","title":"DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field","description":"The BIND resolver accepts validly-signed NSEC records where the \"Next Domain Name\" field points outside the signer's zone.\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.","publishedAt":"2026-07-22T14:16:10.450Z","updatedAt":"2026-07-22T18:51:47.414Z","severity":{"score":8.6,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","source":"isc"},"assigner":"isc","products":["ISC BIND 9"],"affected":[{"vendor":"ISC","product":"BIND 9","defaultStatus":"unaffected","versions":[{"version":"9.11.0","status":"affected","lessThanOrEqual":"9.18.50","versionType":"custom"},{"version":"9.20.0","status":"affected","lessThanOrEqual":"9.20.24","versionType":"custom"},{"version":"9.21.0","status":"affected","lessThanOrEqual":"9.21.23","versionType":"custom"},{"version":"9.11.3-S1","status":"affected","lessThanOrEqual":"9.18.50-S1","versionType":"custom"},{"version":"9.20.9-S1","status":"affected","lessThanOrEqual":"9.20.24-S1","versionType":"custom"}]}],"references":["https://kb.isc.org/docs/cve-2026-13321","https://downloads.isc.org/isc/bind9/9.20.26","https://downloads.isc.org/isc/bind9/9.21.24"],"weaknesses":["CWE-346"],"ingestedAt":"2026-10-29T20:11:00.674Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/13xxx/CVE-2026-13321.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-13321","state":"PUBLISHED","datePublished":"2026-07-22T14:16:10.450Z","dateUpdated":"2026-07-22T18:51:47.414Z","assignerShortName":"isc","assignerOrgId":"404fd4d2-a609-4245-b543-2c944a302a22","dateReserved":"2026-06-25T08:45:35.931Z"},"containers":{"cna":{"title":"DNSSEC Validation Bypass via Out-of-Zone NSEC Next Field","descriptions":[{"lang":"en","value":"The BIND resolver accepts validly-signed NSEC records where the \"Next Domain Name\" field points outside the signer's zone.\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1."}],"affected":[{"vendor":"ISC","product":"BIND 9","defaultStatus":"unaffected","versions":[{"version":"9.11.0","status":"affected","lessThanOrEqual":"9.18.50","versionType":"custom"},{"version":"9.20.0","status":"affected","lessThanOrEqual":"9.20.24","versionType":"custom"},{"version":"9.21.0","status":"affected","lessThanOrEqual":"9.21.23","versionType":"custom"},{"version":"9.11.3-S1","status":"affected","lessThanOrEqual":"9.18.50-S1","versionType":"custom"},{"version":"9.20.9-S1","status":"affected","lessThanOrEqual":"9.20.24-S1","versionType":"custom"}]}],"references":[{"url":"https://kb.isc.org/docs/cve-2026-13321","name":"CVE-2026-13321","tags":["vendor-advisory"]},{"url":"https://downloads.isc.org/isc/bind9/9.20.26","tags":["patch"]},{"url":"https://downloads.isc.org/isc/bind9/9.21.24","tags":["patch"]}],"metrics":[{"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N","baseScore":8.6,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-346","lang":"en","type":"CWE","description":"CWE-346 Origin Validation Error"}]}],"providerMetadata":{"shortName":"isc","orgId":"404fd4d2-a609-4245-b543-2c944a302a22","dateUpdated":"2026-07-22T14:16:10.450Z"},"datePublic":"2026-07-22T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*","versionStartIncluding":"9.11.0","versionEndIncluding":"9.18.50"},{"vulnerable":true,"criteria":"cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*","versionStartIncluding":"9.20.0","versionEndIncluding":"9.20.24"},{"vulnerable":true,"criteria":"cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*","versionStartIncluding":"9.21.0","versionEndIncluding":"9.21.23"},{"vulnerable":true,"criteria":"cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*","versionStartIncluding":"9.11.3-S1","versionEndIncluding":"9.18.50-S1"},{"vulnerable":true,"criteria":"cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*","versionStartIncluding":"9.20.9-S1","versionEndIncluding":"9.20.24-S1"}]}]}],"impacts":[{"descriptions":[{"lang":"en","value":"An attacker controlling any DNSSEC-signed zone can craft NSEC records that span into victim zones, enabling cross-zone cache poisoning with authenticated denial-of-service responses (AD=1)."}]}],"workarounds":[{"lang":"en","value":"No workarounds known."}],"exploits":[{"lang":"en","value":"We are not aware of any active exploits."}],"solutions":[{"lang":"en","value":"Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.26, 9.21.24, or 9.20.26-S1."}],"credits":[{"lang":"en","value":"ISC would like to thank Qifan Zhang of Palo Alto Networks for bringing this vulnerability to our attention."}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-22T18:51:32.344539Z","id":"CVE-2026-13321","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-22T18:51:47.414Z"}}]}}}