WordPress 4.2.3 was recently released. This update was a critical security release for all previous WordPress versions. It is strongly recommended to upgrade WordPress version to WordPress 4.2.3.
WordPress versions 4.2.2 and earlier are affected by a critical cross-site scripting vulnerability, which could allow anonymous users to compromise a site. They have also fixed an issue where it was possible for a user with Subscriber permissions to create a draft through Quick Draft.