Vulnerability · Published Aug 28, 2026 · Assigned by OX
CVE-2026-33607
Medium 4.3
In plain English
A medium-severity uncontrolled resource consumption in OX Dovecot CE from Open-Xchange GmbH. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 46% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
An attacker that has valid credentials can use IMAP LIST command to consume CPU. This can cause degradation or denial of service for IMAP. Monitor system for abnormal CPU usage and kill the offending process and lock account. Alternatively install fixed version. No publicly available exploits are known.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | dovecot | 2.4.5-r0 | ALPINE-CVE-2026-33607 |
| Alpine:v3.24 | dovecot | 2.4.5-r0 | ALPINE-CVE-2026-33607 |
| Debian:12 | dovecot | 1:2.3.19.1+dfsg1-2.1+deb12u7 | DEBIAN-CVE-2026-33607 |
| Debian:13 | dovecot | 1:2.4.1+dfsg1-6+deb13u7 | DEBIAN-CVE-2026-33607 |
| Debian:14 | dovecot | 1:2.4.5+dfsg1-1 | DEBIAN-CVE-2026-33607 |
| Ubuntu:22.04:LTS | dovecot | no fix listed | UBUNTU-CVE-2026-33607 |
| Ubuntu:24.04:LTS | dovecot | no fix listed | UBUNTU-CVE-2026-33607 |
| Ubuntu:26.04:LTS | dovecot | no fix listed | UBUNTU-CVE-2026-33607 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Open-Xchange GmbH | OX Dovecot Pro | 2.3.0 – before 3.0.73.1.0 – before 3.1.6 |
| Open-Xchange GmbH | OX Dovecot CE | 2.3.0 – before 2.4.5 |
Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L