{"id":"ALPINE-CVE-2026-73208","details":"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.","modified":"2026-08-31T08:30:07.478082843Z","published":"2026-08-28T12:16:31.127Z","upstream":["CVE-2026-73208"],"references":[{"type":"ADVISORY","url":"https://security.alpinelinux.org/vuln/CVE-2026-73208"}],"affected":[{"package":{"name":"dovecot","ecosystem":"Alpine:v3.23","purl":"pkg:apk/alpine/dovecot?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2026-73208.json"}},{"package":{"name":"dovecot","ecosystem":"Alpine:v3.24","purl":"pkg:apk/alpine/dovecot?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.4.5-r0"}]}],"ecosystem_specific":{},"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/alpine/ALPINE-CVE-2026-73208.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"}]}