CVE-2026-40878
Published:April 21, 2026
Updated:April 25, 2026
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the mailcow web interface passes the raw "$_SERVER['REQUEST_URI']" to Twig as a global template variable and renders it inside a JavaScript string literal in the "setLang()" helper of "base.twig", relying on Twig's default HTML auto-escaping instead of the context-appropriate "js" escaping strategy. In addition, the "query_string()" Twig helper merges all current "$_GET" parameters into the language-switching links on the login page, so attacker-supplied parameters are reflected and preserved across navigation. Version 2026-03b fixes the vulnerability.
Affected Packages
https://github.com/mailcow/mailcow-dockerized.git (GITHUB):
Affected version(s) >=2022-01 <2026-03bFix Suggestion:
Update to version 2026-03bRelated Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
2.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
ACTIVE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
LOW
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
EPSS
Base Score:
0.05
