Mattermost has a Missing Authorization vulnerability
Moderate severity
GitHub Reviewed
Published
Oct 16, 2025
to the GitHub Advisory Database
•
Updated Oct 16, 2025
Description
Published by the National Vulnerability Database
Oct 16, 2025
Published to the GitHub Advisory Database
Oct 16, 2025
Reviewed
Oct 16, 2025
Last updated
Oct 16, 2025
Mattermost versions 10.10.x <= 10.10.2, 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to validate email ownership during Slack import process which allows attackers to create verified user accounts with arbitrary email domains via malicious Slack import data to bypass email-based team access restrictions.
References