Use-after-free vulnerability in the DisplayObject class in the ActionScript 3 (AS3) implementation in Adobe Flash Player 13.x through 13.0.0.302 on Windows and OS X 14.x through 18.0.0.203 on Windows and OS X 11.x through 11.2.202.481 on Linux and 12.x through 18.0.0.204 on Linux Chrome installations allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted Flash content that leverages improper handling of the opaqueBackground property as exploited in the wild in July 2015.