Received this email just now. A big thanks to ElegantThemes +1 to them.
You are receiving this email because you are an active member of ElegantThemes.com. In the past, our themes have used a popular image re-sizing script called Timthumb (http://www.binarymoon.co.uk/projects/timthumb/). The script is used by millions of sites and is quite popular in the WordPress themeing community. That being said, it was noted yesterday that a vulnerability exists within certain versions of the script (http://code.google.com/p/timthumb/issues/detail?id=212), and therefore this vulnerability may also exist in your theme (depending on when you last updated it). While that author has provided a fix, it is highly recommended that you update all of your EelgantThemes themes to their latest versions. The latest versions of our themes no longer utilize the timthumb script and therefore are not subject to this security hole.
Regardless of when you last updated your theme, I would strongly suggest that everyone update their themes to the latest version and insure that the timthumb.php file and your /cache folder has been removed. To update your theme and remove the file, simply delete your current theme via the Appearances > Themes section of the WordPress Dashboard. Then you can re-download the theme from the members area and re-upload it normally:
The latest theme versions require that your thumbnail images be hosted on the same domain name where WordPress is installed. If you were previously using timthumb.php to allow external image source by editing the file‚s $allowedSites array, then these thumbnails will no longer function.
Before updating the theme, make sure that you are using the latest version of WordPress. I would also disable all of your plugins temporarily before doing any update to insure that no compatibility issues exist. Remember to always keep WordPress, your Themes and your Plugins up-to-date to help protect yourself against any vulnerabilities.
I am sorry for any inconvenience this has caused.