Vulnerability DatabaseCVE-2026-40873
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CVE-2026-40873
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 Quarantine details modal injects attachment filenames into HTML without escaping, allowing arbitrary HTML/JS execution. An attacker can deliver an email with a crafted attachment name so that when an admin views the quarantine item, JavaScript executes in their browser, taking over their account. Version 2026-03b fixes the vulnerability.
Affected Packages
https://github.com/mailcow/mailcow-dockerized.git (GITHUB):
Affected version(s) >=2022-01 <2026-03b
Fix Suggestion:
Update to version 2026-03b
Related Resources (1)
https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-2xjc-rg88-jvpp
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CVSS v4
Base Score:
8.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.6
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
CWE-80
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-79
EPSS
Base Score:
0.08