Vulnerability 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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-73208?
CVE-2026-73208 is a vulnerability with a CVSS score of 7.4 (HIGH). 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 chec...
How severe is CVE-2026-73208?
CVE-2026-73208 has been rated HIGH with a CVSS base score of 7.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-73208?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.