Previewed at WWDC, launching in the fall.
Snow Leopard Installation Downgrades Flash Player to Vulnerable Version
Unfortunately during the course of that update (and unknown to you) Apple downgraded your installation of Flash to an earlier version (version 10.0.23.1), which is known not to be secure and is not patched against various security vulnerabilities.
The version you should be running is the latest version of Flash Player for Mac - 10.0.32.18.
Mac users are not informed that Snow Leopard has downgraded their version of Flash without permission, and that they are now exposed to a raft of potential attacks and exploits which have been targeted on Adobe's software in recent months.