An issue was discovered in Adobe Acrobat Reader 2018.009.20050 and earlier versions, 2017.011.30070 and earlier versions, 2015.006.30394 and earlier versions. This vulnerability occurs as a result of computation that reads data that is past the end of the target buffer; the computation is part of the TIFF processing in the XPS module. A successful attack can lead to sensitive data exposure.
https://helpx.adobe.com/security/products/acrobat/apsb18-02.html