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 write specific Twig code to escape the Twig sandbox and execute arbitrary PHP. This issue has been patched in 3.4.15.

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.

October is a Content Management System (CMS) and web platform to assist with development workflow. A user with access to the media manager that stores SVG files could create a stored XSS attack against themselves and any other user with access to the media manager when SVG files are supported. This issue has been patched in version 3.5.2.