The zero-day bug is a universal cross-site scripting issue. Google tipped their hand on this yesterday.
Adobe today released an update for Flash Player which fixes 5 critical vulnerabilities and an important universal cross-site scripting issue that they report is being exploited in the wild in targeted attacks.
The last vulnerability being universal, all versions of Flash Player are affected. Updates are available now for Adobe Flash Player 10.3.183.7 and earlier versions for Windows, Macintosh, Linux and Solaris, and Adobe Flash Player 10.3.186.6 and earlier versions for Android. The new versions are 10.3.183.10 for Windows, Macintosh, Linux and Solaris; 10.3.186.7 for Android.
Some time soon you can expect updates to Acrobat and Reader, as those products incorporate full Flash Player functionality, although only for the 5 critical vulnerabilities. Adobe says that the Flash component in Adobe Reader and Acrobat is not affected by the cross-site scripting bug that is being exploited in the wild.
Google made this fix available for Chrome in an update yesterday.