Adobe Acrobat Reader versions 11.0.19 and earlier, 15.006.30280 and earlier, 15.023.20070 and earlier have an exploitable use after free vulnerability in the JavaScript API related to the collaboration functionality. Successful exploitation could lead to arbitrary code execution.
https://helpx.adobe.com/security/products/acrobat/apsb17-11.html
http://www.zerodayinitiative.com/advisories/ZDI-17-282/