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 is an instance of a heap overflow vulnerability in the JavaScript engine. The vulnerability is triggered by a PDF file with crafted JavaScript code that manipulates the optional content group (OCG). A successful attack can lead to code corruption, control-flow hijack, or a code re-use attack.