It has been found that the latest version of Apple's operating system, Mac OS X 10.6 Snow Leopard, automatically downgrades a user's version of Flash to 10.0.23.1. The most current version of Flash, and the one most users who regularly update their software should have installed, is 10.0.32.18.
Unfortunately for the many users that had the latest version of Flash installed before they purchased Snow Leopard, the installation downgraded their software without their knowledge. Security experts will agree that Adobe is quickly becoming a favorite target for hackers and malware producers.
The best course of action is to immediately update your version of Flash if you have installed Snow Leopard. If you are not sure which version of Flash you are running, visit this Adobe KB Article, and it will let you know.