Blog software provider WordPress has just released the 3.0.5 version of their blogging software. They suggest that if you are running WordPress you update immediately.
This security release fixes two XSS bugs, some update to the media uploader to prevent information disclosure and some enhancements to harden the overall blogging tool.
You can update using the auto-updater within your WordPress admin or you can download the files from wordpress.org.
It was just over a month ago that WordPress released version 3.0.4 which was also a security release.