Service announcements
2015-04-21 23:07: WordPress 4.1.2 - security updateWordPress has released version 4.1.2, which is a critical security update. All previous versions are vulnerable, and must be updated immediately.
Source: wordpress.org
WordPress 3.9 and more recent versions usually update automatically, but double-check by logging in to wp-admin. Ensure that all plugins and themes are up to date.