{"id":"CVE-2026-19033","state":"PUBLISHED","title":"Unauthenticated IXFR deltas are applied to the live zone before TSIG verification","description":"For a secondary zone with transfers restricted by TSIG, `named` may start to serve the data provided in a zone transfer before the final message with the TSIG signature arrives. This could allow an attacker that does not actually possess a valid TSIG signature to send unauthorized zone contents to a secondary server. Although no TSIG signature ever arrives, `named` does not rollback to the pre-transfer state. To exploit the vulnerability, the transfer must be a multi-message TCP IXFR, as described by RFC 8945.\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.","publishedAt":"2026-09-16T14:10:08.535Z","updatedAt":"2026-09-17T17:36:48.716Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L","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":"9.20.27","versionType":"custom"},{"version":"9.21.0","status":"affected","lessThanOrEqual":"9.21.25","versionType":"custom"},{"version":"9.11.3-S1","status":"affected","lessThanOrEqual":"9.18.50-S1","versionType":"custom"},{"version":"9.20.9-S1","status":"affected","lessThanOrEqual":"9.20.27-S1","versionType":"custom"}]}],"references":["https://kb.isc.org/docs/cve-2026-19033","https://downloads.isc.org/isc/bind9/9.20.29","https://downloads.isc.org/isc/bind9/9.21.26"],"weaknesses":["CWE-349"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/19xxx/CVE-2026-19033.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-19033","state":"PUBLISHED","datePublished":"2026-09-16T14:10:08.535Z","dateUpdated":"2026-09-17T17:36:48.716Z","assignerShortName":"isc","assignerOrgId":"404fd4d2-a609-4245-b543-2c944a302a22","dateReserved":"2026-08-06T04:18:09.842Z"},"containers":{"cna":{"title":"Unauthenticated IXFR deltas are applied to the live zone before TSIG verification","descriptions":[{"lang":"en","value":"For a secondary zone with transfers restricted by TSIG, `named` may start to serve the data provided in a zone transfer before the final message with the TSIG signature arrives. This could allow an attacker that does not actually possess a valid TSIG signature to send unauthorized zone contents to a secondary server. Although no TSIG signature ever arrives, `named` does not rollback to the pre-transfer state. To exploit the vulnerability, the transfer must be a multi-message TCP IXFR, as described by RFC 8945.\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-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":"9.20.27","versionType":"custom"},{"version":"9.21.0","status":"affected","lessThanOrEqual":"9.21.25","versionType":"custom"},{"version":"9.11.3-S1","status":"affected","lessThanOrEqual":"9.18.50-S1","versionType":"custom"},{"version":"9.20.9-S1","status":"affected","lessThanOrEqual":"9.20.27-S1","versionType":"custom"}]}],"references":[{"url":"https://kb.isc.org/docs/cve-2026-19033","name":"CVE-2026-19033","tags":["vendor-advisory"]},{"url":"https://downloads.isc.org/isc/bind9/9.20.29","tags":["patch"]},{"url":"https://downloads.isc.org/isc/bind9/9.21.26","tags":["patch"]}],"metrics":[{"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"LOW","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L","baseScore":6.5,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-349","lang":"en","type":"CWE","description":"CWE-349 Acceptance of Extraneous Untrusted Data With Trusted Data"}]}],"providerMetadata":{"shortName":"isc","orgId":"404fd4d2-a609-4245-b543-2c944a302a22","dateUpdated":"2026-09-16T14:10:08.535Z"},"datePublic":"2026-09-16T00:00:00.000Z","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":"9.20.27"},{"vulnerable":true,"criteria":"cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*","versionStartIncluding":"9.21.0","versionEndIncluding":"9.21.25"},{"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":"9.20.27-S1"}]}]}],"impacts":[{"descriptions":[{"lang":"en","value":"A successful attack may result in arbitrary attacker-supplied data being added to a zone."}]}],"workarounds":[{"lang":"en","value":"No workarounds known."}],"exploits":[{"lang":"en","value":"This flaw was discovered in internal testing. 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: 9.20.29, 9.21.26, or 9.20.29-S1."}],"source":{"discovery":"INTERNAL"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-17T17:36:40.215995Z","id":"CVE-2026-19033","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-17T17:36:48.716Z"}}]}}}