The Qubely WordPress plugin before 1.8.5 does not validate and escape some of its block options before outputting them back in a page/post where the block is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.
The Qubely WordPress plugin before 1.8.6 allows unauthenticated user to send arbitrary e-mails to arbitrary addresses via the qubelysendformdata AJAX action.
The Qubely WordPress plugin before 1.7.8 does not have authorisation and CSRF check on the qubelydeletesavedblock AJAX action, and does not ensure that the block to be deleted belong to the plugin, as a result, any authenticated users, such as subscriber can delete arbitrary posts