Mattermost Improper Validation of Specified Type of Input vulnerability

Mattermost versions 10.2.0, 9.11.x = 9.11.5, 10.0.x = 10.0.3, 10.1.x = 10.1.3 fail to properly validate post types, which allows attackers to deny service to users with the sysconsolereadplugins permission via creating a post with the customplnotification type and specific props...