You are responsible for maintaining your WordPress site and keeping it up-to-date. Wordpress.org provides instructions on how to update WordPress.
*Note that the newer versions of WordPress require a hosting environment that supports recent versions of PHP and MySQL, and Stanford's AFS environment eventually will not meet those requirements; as a result, websites built using WordPress on AFS may not function as expected. Additional information can be found on the WCMS WordPress Hosting project page.
For help, submit a Help ticket or visit the Stanford University WordPress Community of Practice.