If you have a self hosted WordPress site, this recent release by WordPress developers is important for the security of your site.
According to WordPress.org
WordPress 4.2.1 is now available. This is a critical security release for all previous versions and we strongly encourage you to update your sites immediately.
This came after the WordPress team was “made aware of a cross-site scripting vulnerability, which could enable commenters to compromise a site”. The vulnerability was discovered by Jouko Pynnönen.
WordPress 4.2.1 has begun to roll out as an automatic background update, for sites that support those.
As a WordPress user, it is important to stay abreast of releases by the developers, which you can usually find in your dashboard. If you have not made changes to the layout of your dashboard, you should see a feed from WordPress.or on the right side, which looks something like this:
Download WordPress 4.2.1 or venture over to Dashboard → Updates and simply click “Update Now”.