CVE-2026-27855
CVSS Score
6.8
EPSS Score
0.0%
EPSS Percentile
11th
Dovecot OTP authentication is vulnerable to replay attack under specific conditions. If auth cache is enabled, and username is altered in passdb, then OTP credentials can be cached so that same OTP reply is valid. An attacker able to observe an OTP exchange is able to log in as the user. If authentication happens over unsecure connection, switch to SCRAM protocol. Alternatively ensure the communcations are secured, and if possible switch to OAUTH2 or SCRAM. No publicly available exploits are known.
| CWE | CWE-294 |
| Vendor | open-xchange gmbh |
| Product | ox dovecot pro |
| Published | Mar 27, 2026 |
| Last Updated | Mar 27, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
Open-Xchange GmbH / OX Dovecot Pro
0 ≤ 2.3.0