Edison Mail Sync Bug Allowing Access to Other Users' Email Accounts [Updated]

Several users of popular email app Edison Mail this morning are reporting that they are able to see email accounts of other users within the iOS app. In what appears to be a major privacy breach, users report that after enabling a new sync feature, they have full access to these other email accounts.
The new sync feature was recently rolled out by Edison to allow connected email accounts to show up across all of your devices, but clearly something has gone significantly wrong with the feature.I