Unspecified vulnerability in Adobe Flash Player 21.0.0.242 and earlier, as used in the Adobe Flash libraries in Microsoft Internet Explorer 10 and 11 and Microsoft Edge, has unknown impact and attack vectors, a different vulnerability than other CVEs listed in MS16-083.
https://helpx.adobe.com/security/products/flash-player/apsb16-18.html
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2016/ms16-083