October CMS safe mode bypass using Page template injection

October is a Content Management System (CMS) and web platform to assist with development workflow. An authenticated backend user with the `editor.cms_pages`, `editor.cms_layouts`, or `editor.cms_partials` permissions who would normally not be permitted to provide PHP code to be executed by the CMS due to `cms.safe_mode` being enabled can craft a special request to include PHP code in the CMS template. This issue has been patched in version 3.4.15.