VULNERABILITY INTELLIGENCE
CVE-2026-40875
EPSS probability0.24%
CISA KEVNot currently listed
Published2026-04-21
Last modified2026-10-26
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.
Weakness classification
- security-advisories@github.com: CWE-79