Security concerns have led Apple to use its built-in malware protection system to disable Adobe Flash version 11.8.800.94 and earlier on Macs on Tuesday.
The lockdown means that only the most recent version of Flash, 11.8.800.168, will run on OS X Snow Leopard, Lion, and Mountain Lion.
The vulnerabilities could allow attackers to take control of a user’s system and run malicious code.
You can check to see which version of Flash you’re running by running System Preferences, going to the Flash Player pane, and clicking on the Advanced tab. Flash can then be updated from there if needed, or you can visit the Adobe Flash Player website to download the update.