Different Teams can see all other Mattermost members via “Add new members to team” link. Even worse they can even add other teams members as regular user.

Expected behavior

Teams are meant to seperate Accounts.
A regular User should not have the privilege to see all other server members nor to invite them.
Observed behavior

ALL Users are visible as non privileged user.
ALL User can be invited as non privileged user.

As mentioned in:
https://forum.mattermost.org/t/regular-team-users-can-see-all-other-servermembers-and-can-invite-them-to-their-team/6838/7