Information Exposure Affecting dovecot package, versions [2.3.0,2.4.5)
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-2026-40203 (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 Information Exposure in the IMAP compression process. An attacker can infer the content of small messages by sending crafted emails to a user and monitoring the sizes of IMAP responses, thereby confirming whether a message body matches a guessed value.
Workaround
This vulnerability can be mitigated by disabling IMAP compression in the configuration and restarting the service.