CVE-2026-40014
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
An attacker that can send mail to a user can craft a message header that makes the IMAP THREAD command consume CPU disproportionate to the size of the message. When a mail client issues a THREAD command on the affected mailbox, this can cause degradation or denial of service for IMAP. Monitor system for abnormal CPU usage, kill the offending process and remove the offending message from the affected mailbox. 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:R/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
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