{"id":"CVE-2026-73208","state":"PUBLISHED","title":"An attacker that holds a token intended for a different purpose can authenticate, because when an OAuth2 token response does not contain a scope claim, the audience claim is used i","description":"An attacker that holds a token intended for a different purpose can authenticate, because when an OAuth2 token response does not contain a scope claim, the audience claim is used in its place and checked against the configured required scopes. These are different concepts, and the audience claim does not describe what a token is allowed to do. A token that grants no relevant permissions can be accepted because its intended recipient value happens to match a configured scope name, granting access that should have been denied. It also hides an identity provider misconfiguration where scopes are not being issued at all. Ensure the identity provider issues a scope claim for all tokens used with Dovecot, and that configured scope names do not match audience values. Update to non-vulnerable version. No publicly available exploits are known.","publishedAt":"2026-08-28T10:12:32.679Z","updatedAt":"2026-08-28T15:53:21.257Z","severity":{"score":7.4,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","source":"OX"},"assigner":"OX","products":["Open-Xchange GmbH OX Dovecot Pro","Open-Xchange GmbH OX Dovecot CE"],"affected":[{"vendor":"Open-Xchange GmbH","product":"OX Dovecot Pro","defaultStatus":"unaffected","versions":[{"version":"2.3.13","status":"affected","lessThan":"2.3.22.2","versionType":"semver"},{"version":"3.0.0","status":"affected","lessThan":"3.0.7","versionType":"semver"},{"version":"3.1.0","status":"affected","lessThan":"3.1.6","versionType":"semver"}],"modules":["core"]},{"vendor":"Open-Xchange GmbH","product":"OX Dovecot CE","defaultStatus":"unaffected","versions":[{"version":"2.3.13","status":"affected","lessThan":"2.4.5","versionType":"semver"}],"modules":["core"]}],"references":["https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/73xxx/CVE-2026-73208.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73208","state":"PUBLISHED","datePublished":"2026-08-28T10:12:32.679Z","dateUpdated":"2026-08-28T15:53:21.257Z","assignerShortName":"OX","assignerOrgId":"8ce71d90-2354-404b-a86e-bec2cc4e6981","dateReserved":"2026-08-11T13:14:10.017Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"An attacker that holds a token intended for a different purpose can authenticate, because when an OAuth2 token response does not contain a scope claim, the audience claim is used in its place and checked against the configured required scopes. These are different concepts, and the audience claim does not describe what a token is allowed to do. A token that grants no relevant permissions can be accepted because its intended recipient value happens to match a configured scope name, granting access that should have been denied. It also hides an identity provider misconfiguration where scopes are not being issued at all. Ensure the identity provider issues a scope claim for all tokens used with Dovecot, and that configured scope names do not match audience values. Update to non-vulnerable version. No publicly available exploits are known."}],"affected":[{"vendor":"Open-Xchange GmbH","product":"OX Dovecot Pro","defaultStatus":"unaffected","versions":[{"version":"2.3.13","status":"affected","lessThan":"2.3.22.2","versionType":"semver"},{"version":"3.0.0","status":"affected","lessThan":"3.0.7","versionType":"semver"},{"version":"3.1.0","status":"affected","lessThan":"3.1.6","versionType":"semver"}],"modules":["core"]},{"vendor":"Open-Xchange GmbH","product":"OX Dovecot CE","defaultStatus":"unaffected","versions":[{"version":"2.3.13","status":"affected","lessThan":"2.4.5","versionType":"semver"}],"modules":["core"]}],"references":[{"url":"https://documentation.open-xchange.com/dovecot/security/advisories/csaf/2026/oxdc-adv-2026-0003.json","tags":["vendor-advisory"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","description":"Improper Authentication","lang":"en","type":"cwe"}]}],"providerMetadata":{"shortName":"OX","orgId":"8ce71d90-2354-404b-a86e-bec2cc4e6981","dateUpdated":"2026-08-28T10:31:03.865Z"},"source":{"defect":"DOV-9309","discovery":"INTERNAL"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-28T15:14:37.239590Z","id":"CVE-2026-73208","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-28T15:53:21.257Z"}}]}}}