After approximately 13 million downloads of WordPress 4.8, a maintenance release is available now.
The new maintenance release contains 29 fixes and some enhancements. The most notable are fixes to the rich Text widget and the introduction of the Custom HTML widget.
For a full list of changes, consult the release notes, the tickets closed, and the list of changes.
Download WordPress 4.8.1 or visit Dashboard → Updates and simply click “Update Now.” Sites that support automatic background updates are already beginning to update to WordPress 4.8.1.
Source: https://wordpress.org/news/2017/08/wordpress-4-8-1-maintenance-release/