CVE-2026-40875

high

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.

References

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

Details

Source: Mitre, NVD

Published: 2026-04-21

Updated: 2026-04-22

Risk Information

CVSS v2

Base Score: 4.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 6.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Severity: Medium

CVSS v4

Base Score: 7

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:H/VI:N/VA:N/SC:H/SI:H/SA:N

Severity: High

EPSS

EPSS: 0.00047