WordPress 4.8.1 is now available for download from your WordPress Dashboard. Even though It’s a minor release this version contains 29 bug fixes and various enhancements. The most notable one is the introduction of a dedicated Custom HTML widget.
Custom HTML Widget in WordPress 4.8.1
The existing text editor has been improved to automatically detect HTML code and display a notice to use the “Text” tab instead.
If you are already on the “Text” tab it encourages you to use the new custom HTML widget for adding custom code your site.