Flash Player versions 31.0.0.153 and earlier, and 31.0.0.108 and earlier have a use after free vulnerability. Successful exploitation could lead to arbitrary code execution.
Published: 2018-12-05
Adobe has issued an out-of-band advisory for CVE-2018-15982. Through the use of a maliciously crafted RAR file, an attacker exploiting this vulnerability can take over the machine of users that run it.
https://www.exploit-db.com/exploits/46051/
https://helpx.adobe.com/security/products/flash-player/apsb18-42.html