CVE-2026-42391
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
An unauthenticated attacker can send an IMAP ID command with a very large number of parameters before logging in, which causes memory and CPU usage to grow disproportionately. The login process can be terminated by the out-of-memory handling, which also terminates all other connections handled by the same process. This can cause degradation or denial of service for IMAP logins. Limit the number of connections handled by a single imap-login process. This has a performance impact though. Update to non-vulnerable version. No publicly available exploits are known.
| CWE | CWE-400 |
| Vendor | open-xchange gmbh |
| Product | ox dovecot pro |
| Published | Aug 28, 2026 |
| Last Updated | Aug 28, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
Open-Xchange GmbH / OX Dovecot Pro
2.3.0 < 2.3.22.2 3.0.0 < 3.0.7 3.1.0 < 3.1.6
Open-Xchange GmbH / OX Dovecot CE
2.3.0 < 2.4.5