You should update Adobe Flash Player right now.
Firefox is up to date, but your current version of Flash Player can cause security and stability issues. Please install the free update as soon as possible.
Unfortunately, their script doesn't understand that Flash Player version 126.96.36.199 is a "fixed" version, and no update is necessary or appropriate. (Source: APSB09-10)
Shame on you, Mozilla, for needlessly frightening your customers.