FLASH SECURITY ALERT
This morning a major WordPress secuirty risk was uncovered involving two of the most widely used WordPress caching plugins.
The security hole allows for execution of code directly on your host server which, in-turn, allows hackers to access to alter, modify or delete files on the server. An attacker can also grant themselves access to read your WordPress database giving them the ability, among other things, to add or modify users and download user information.
To update the plugin goto your admin dashboard, click plugins, scroll to the plugin you have installed and click update now.
You can read more about this on the Sucuri forums.