CVE-2026-40019
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th
An unauthenticated attacker can send a truncated quoted argument to the ManageSieve login process, which makes it spin in an infinite loop consuming CPU. This can cause degradation or denial of service for Sieve script management, and repeated connections can consume all available CPU on the server. Monitor system for abnormal CPU usage and kill the offending process. Restrict network access to the ManageSieve service to trusted clients. Update to non-vulnerable version. No publicly available exploits are known.
| CWE | CWE-400 |
| Vendor | open-xchange gmbh |
| Product | ox dovecot ce |
| Published | Aug 28, 2026 |
| Last Updated | Aug 28, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
Open-Xchange GmbH / OX Dovecot CE
2.4.3 < 2.4.5