Impact

For regular (non-LiveQuery) queries, the session token is removed from the response, but for LiveQuery payloads it is currently not. If a user has a LiveQuery subscription on the Parse.User class, all session tokens created during user sign-ups will be broadcast as part of the LiveQuery payload.

Patches

Remove session token from LiveQuery payload.

Workaround

Set user.acl(new Parse.ACL()) in a beforeSave trigger to make the user private already on sign-up.