Adobe has identified vulnerabilities in its Flash player and today, released an update to fix them. Be sure to visit www.adobe.com with both Internet Explorer and Firefox to install the update.
Here's more about the problem: http://www.adobe.com/support/security/bulletins/apsb09-10.html
People ask frequently if they should update things like Flash, Shockwave, Java and Adobe Reader when prompted. The answer is Yes! Usually, it's a patch to fix a security problem. The updates take very little time and could save you from a big problem.
Your security and update routine should include updating these add-ons on a regular basis, whether you've been prompted or not. I'll list some update links next time.