The WordPress team has been quick to act on a vulnerability in the Snoopy library that was announced today. 2.6.3 is available for download.
Only two files have been updated and as usual I’ve made a single file that you can use to upgrade your WordPress 2.6.2 installation to 2.6.3.
Download the file below and unzip it into your blog root. Run /wp-admin/upgrade.php
If you are running a 2.6.1 or 2.6 then you will need to first update your blog to 2.6.2.