On 20 Apr, 2017, WordPress 3.9.18 was released to the public.
To download WordPress 3.9.18, update automatically from the Dashboard > Updates menu in your site’s admin area or visit https://wordpress.org/download/release-archive/.
For step-by-step instructions on installing and updating WordPress:
If you are new to WordPress, we recommend that you begin with the following:
- New To WordPress – Where to Start
- First Steps With WordPress or Upgrading WordPress Extended
- WordPress Lessons
From the WordPress 4.7.4 release post: WordPress 3.9.18 contains 47 maintenance fixes and enhancements from Version 3.9.17, including an incompatibility between the upcoming Chrome version and the visual editor, and inconsistencies in media handling. For more information, consult the list of changes.