Adobe Flash Player versions 28.0.0.161 and earlier have an exploitable use after free vulnerability. Successful exploitation could lead to arbitrary code execution in the context of the current user.
https://helpx.adobe.com/security/products/flash-player/apsb18-05.html
https://euvd.enisa.europa.eu/vulnerability/EUVD-2018-16704
https://access.redhat.com/errata/RHSA-2018:0520