WordPress 4.8.1 is available for download or as an update from the WordPress Dashboard. This release contains 29 bug fixes and improvements. The most notable addition is a dedicated Custom HTML widget.

The Custom HTML widget works similar to the Text widget in WordPress 4.7 and below. To see a full list of changes in WordPress 4.8.1, check out the release notes. If you think you’ve discovered a bug, please report it in as much detail as possible on the WordPress support forums. Twenty-two people contributed to this release.
This is awesome! They should have added this a long time ago but I guess better late than never.