Adobe Flash Player versions 25.0.0.171 and earlier have an exploitable use after free vulnerability during internal computation caused by multiple display object mask manipulations. Successful exploitation could lead to arbitrary code execution.
https://security.gentoo.org/glsa/201707-15
https://helpx.adobe.com/security/products/flash-player/apsb17-17.html
https://access.redhat.com/errata/RHSA-2017:1439