Blocks access to both /pex & /permissionsex from everyone except Console.
Prevents Griefing and server crash exploit.
Recently a player from my server did /pex user a group set number.
That generated a list of uuids and displayed it to the player, causing the server to crash, so to avoid anyone being able to do this. Here's a plugin.
Also I tried revoking the permission and that failed, so anyone with pex and want's a quick fix. Here.