CVE-2026-40875
HIGH EPSS 8.0%
Published Apr 21, 20262mo ago · Modified Jun 17, 20261w ago
7.0 CVSS 4.0
Published Apr 21, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Network
Attack Complexity High
Privileges Required Low
User Interaction P
Scope X
Threat Intelligence
EPSS Exploit Probability
8.0% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 2
CWE-79 Cross-site Scripting Injection
CWE-80
References 1
- github.com https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jprq-w83q-q62h
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.