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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 01 Sep 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Open-xchange
Open-xchange ox Dovecot Ce Open-xchange ox Dovecot Pro |
|
| Vendors & Products |
Open-xchange
Open-xchange ox Dovecot Ce Open-xchange ox Dovecot Pro |
Tue, 01 Sep 2026 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Title | OAuth2 Token Misuse Enables Unauthorized Authentication | dovecot: Dovecot: Authentication bypass via incorrect OAuth2 token validation |
| Weaknesses | CWE-303 | |
| References |
| |
| Metrics |
threat_severity
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threat_severity
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Fri, 28 Aug 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Title | OAuth2 Token Misuse Enables Unauthorized Authentication |
Fri, 28 Aug 2026 11:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Weaknesses | CWE-287 | |
| References |
| |
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: OX
Published:
Updated: 2026-08-28T15:53:21.257Z
Reserved: 2026-08-11T13:14:10.017Z
Link: CVE-2026-73208
No data.
Status : Received
Published: 2026-08-28T12:16:31.127
Modified: 2026-08-28T20:19:45.063
Link: CVE-2026-73208
OpenCVE Enrichment
Updated: 2026-09-01T15:00:11Z