What’s Vulnerable › Vulnerabilities

CVE-2025-53909: mailcow: dockerized vulnerable to SSTI in Quota and Quarantine Notification Template

• Severity: high (CVSS 7.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-07-17 · updated 2026-06-17
• Weakness: CWE-1336

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.

Affected products

• mailcow-dockerized: before 2025-07 — fixed in 2025-07

How to fix

Upgrade to a fixed version: mailcow-dockerized 2025-07. Check the vendor advisory for mitigations.

References

• https://github.com/mailcow/mailcow-dockerized/commit/8c5f6c03214a4b2bdbf3c78932f860eee949012b
• https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-8p7g-6cjj-wr9m

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