It was exciting to read about the new feature of WordPress 2.3 where it gives notifications as soon as the updated versions of WordPress core and the plugins are released. When I logged into my WordPress 2.3 administration dashboard today, I got my first notification of an updated core version released! (Not news to me though, as the wp-testers list keeps me updated.)

At the top:
Wordpress 2.3 notification for WordPress 2.3.1 core release
In the footer:
Wordpress 2.3 notification for WordPress 2.3.1 core release
WordPress 2.3.1 was released a few hours ago and some of the bugs that it fixes are:

Fixes the security issue related to “an XSS problem that can be exploited if your php setup has register_globals enabled.”

A quick upgrade guide is available on the WordPress Codex. Detailed instructions are also available, in case you have never upgraded WordPress before.

If you, like me, had installed WordPress 2.3 by directly checking out from the Subversion repository, you can upgrade by simply running this from the console:

sh# cd <your-blog-directory>
sh# svn sw http://svn.automattic.com/wordpress/tags/2.3.1/

Substitute the path to your WordPress installation path in place of <your-blog-directory>. Then run http://<your-blog-address>/wp-admin/upgrade.php as usual.
More information on Subversion upgrade.