Vulnerability Description
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.
Related Weaknesses (CWE)
References
- https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q
- https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q
FAQ
What is CVE-2026-40875?
CVE-2026-40875 is a documented vulnerability. 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 fro...
How severe is CVE-2026-40875?
CVSS scoring is not yet available for CVE-2026-40875. Check NVD for updates.
Is there a patch for CVE-2026-40875?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.