The latest version of WordPress Version 2.3.3 has now been released and it is billed as an urgent security release. It seems a flaw has been discovered in the XML-RPC implementation if you have user registration enabled on your blog. The flaw basically allows a registered user to employ a specially crafted request in order to allow them to edit posts on your blog.
Also, this new Version 2.3.3 release fixes a few minor bugs. There are a couple of options if you want to avoid this latest security threat to your blog. Firstly, if you are only interested only in the security fix you can download the fixed version of xmlrpc.php and copy it over your existing xmlrpc.php, or secondly, you can get the new Wordpress 2.3.3 version here and overwrite your existing installation files directly.
So, this could be a good time to update your own Wordpress installation!