CVE-2026-40875

mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the user dashboard's "Seen successful connections" (login history) renders the client IP from login logs without HTML escaping. Because the server trusts the X-Real-IP header as the source IP for logging, an attacker can inject HTML/JS into this field. This Self-XSS can be exploited by a Login CSRF to force the victim into the attacker's account, and then read emails in a previous browser tab. Version 2026-03b fixes the vulnerability.

The following products are affected by CVE-2026-40875 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-40875.

URL	Resource
https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h