Vulcan/packages/vulcan-subscribe/lib/permissions.js

import Users from 'meteor/vulcan:users';

const membersActions = [
  'posts.subscribe',
  'posts.unsubscribe',
  'users.subscribe',
  'users.unsubscribe',
  'categories.subscribe',
  'categories.unsubscribe',
];

Users.groups.members.can(membersActions);