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.

CVSS

No CVSS.

References

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

Configurations

No configuration.

History

21 Apr 2026, 21:16

Type	Values Removed	Values Added
References	~~() https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h -~~	() https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h -

21 Apr 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-21 20:17

Updated : 2026-04-22 21:02

NVD link : CVE-2026-40875

Mitre link : CVE-2026-40875

CVE.ORG link : CVE-2026-40875

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-80

Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

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