Vulnerability · Published Aug 28, 2026 · Assigned by OX
CVE-2026-73209
Medium 6.5
In plain English
A medium-severity security flaw 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 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
An attacker that has valid credentials can send crafted compressed data that causes the affected process to exhaust its stack and crash. The affected process is terminated, which can cause degradation or denial of service for IMAP. Update to non-vulnerable 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-2026-73209 |
| Alpine:v3.24 | dovecot | 2.4.5-r0 | ALPINE-CVE-2026-73209 |
| Debian:12 | dovecot | 1:2.3.19.1+dfsg1-2.1+deb12u7 | DEBIAN-CVE-2026-73209 |
| Debian:13 | dovecot | 1:2.4.1+dfsg1-6+deb13u7 | DEBIAN-CVE-2026-73209 |
| Debian:14 | dovecot | 1:2.4.5+dfsg1-1 | DEBIAN-CVE-2026-73209 |
| Ubuntu:22.04:LTS | dovecot | no fix listed | UBUNTU-CVE-2026-73209 |
| Ubuntu:24.04:LTS | dovecot | no fix listed | UBUNTU-CVE-2026-73209 |
| Ubuntu:26.04:LTS | dovecot | no fix listed | UBUNTU-CVE-2026-73209 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Open-Xchange GmbH | OX Dovecot Pro | 2.3.0 – before 2.3.22.23.0.0 – 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-674 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H