CVE-2025-53909

Critical

Description

mailcow: dockerized is an open source groupware/email suite based on docker. A Server-Side Template Injection (SSTI) vulnerability exists in versions prior to 2025-07 in the notification template system used by mailcow for sending quota and quarantine alerts. The template rendering engine allows template expressions that may be abused to execute code in certain contexts. The issue requires admin-level access to mailcow UI to configure templates, which are automatically rendered during normal system operation. Version 2025-07 contains a patch for the issue.

SeverityCritical
CVSS9.1
Exploit probability—
ProductMailcow\
PublishedJul 17, 2025
First seenJul 17, 2025
Weakness typeCWE-1336CWE-1336

How to fix

Update
  • mailcow mailcow\2025-07 or later

Affected products

ProductAffected versionsFixed in
mailcow mailcow\_dockerized ≤ v < 2025-072025-07

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