GHSA-RP4V-QC77-PHM4 Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15, 10.11.x = 10.11.16 fail to restrict roleupdated websocket event broadcasts to members of the affected team or channel, which allows an authenticated attacker with guest-level access to observe permission scheme change...