Incorrect Implementation of Authentication Algorithm Affecting dovecot package, versions [2.3.11.2,2.4.5)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published24 Sept 2026
- disclosed28 Aug 2026
- creditUnknown
Introduced: 28 Aug 2026
CVE-2026-40205 (opens in a new tab)How to fix?
Upgrade dovecot to version 2.4.5 or higher.
Overview
Affected versions of this package are vulnerable to Incorrect Implementation of Authentication Algorithm in the remote OAuth2 token validation process. An attacker can gain unauthorized access by presenting a token that contains only a subset of the required scopes, as the process fails to enforce all configured authorization policies.
Workaround
This vulnerability can be mitigated by configuring the system to use local OAuth2 token validation instead of remote validation, ensuring all required scopes are enforced during authentication.