This is rated "critical" as it is being exploited in the wild and allows an attacker to completely take over your computer. Everything is vulnerable - Windows (Edge and Internet Explorer), Mac, ChromeOS, and Linux. Strangely, the listed for "Priority" for Linux is lower than for the others, although there's no explanation why. My recommendation to those of y'all on Linux is to upgrade.
Patch is available here.
It may just be better to remove Flash (uninstall it). Most of the major Internet video sites such as Youtube do not use it, and Flash is a sewer of security fail. Uninstalling it will prevent you from having to install the next critical emergency patch.