CVE-2026-52687
Reported by OX · Published August 28, 2026
An attacker that has valid credentials can select a compression algorithm for the IMAP connection whose decompression state requires a large amount of memory, and open several such connections. The memory limit of the process is reached with only a few connections, terminating the process and all connections it handles, which can cause degradation or denial of service for IMAP. Disable IMAP compression. Alternatively limit the number of connections handled by a single imap-login process, though this has a performance impact. Update to non-vulnerable version. No publicly available exploits are known.
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Open-Xchange GmbH | OX Dovecot Pro | 2.3.11, 3.0.0, 3.1.0 |
| Open-Xchange GmbH | OX Dovecot CE | 2.3.11 |
| Open-Xchange GmbH | OX Dovecot Pro | 3.1.0, 2.3.11, 3.0.0 |
| alpine | dovecot | 0, 0, 0 |
| Open-Xchange GmbH | OX Dovecot CE | 2.3.11 |
Timeline
- Aug 28, 2026 CVE Published
- Aug 29, 2026 EPSS Score
- Sep 2, 2026 EPSS Score
- Sep 2, 2026 Security Advisory
- Sep 6, 2026 EPSS Score
- Sep 9, 2026 EPSS Score
- Sep 12, 2026 EPSS Score
- Sep 16, 2026 EPSS Score
- Sep 18, 2026 EPSS Score
- Sep 24, 2026 EPSS Score
- Sep 26, 2026 EPSS Score
- Sep 29, 2026 EPSS Score