It's important to keep WordPress up to date
As Wordpress along with other open source software is freely available and widely used, many exploits can become available from time to time. Becuase this is a large security risk for anyone running Wordpress, they have released a new version to close those security holes. It is critical that you always keep your content management systems such as Wordpress up to date at all time to avoid the possiblity of becoming hacked.
Please upgrade your Wordpress sites to the newest security release now
On 9/11/2013, Wordpress released a major security update to keep your site more secure from potential attacks. Updating your Wordpress site as well as updating any plugins that you may have installed immediately will greatly reduce, or completely prevent injection attacks that can cause your website to be defaced to otherwise removed. Wordpress' full news report on this release is also available for more infromation on this version.