If you use Adobe Acrobat Reader, update your copy by choosing Help > Check for Updates. Security researcher Yuebin Sun of Tencent Security Xuanwu Lab has discovered multiple vulnerabilities that could allow a local attacker to gain root access to your Mac. Fortunately, Adobe has already fixed these vulnerabilities in the latest versions of Acrobat Reader.
Most Mac users shouldn’t need to use Acrobat Reader; macOS’s built-in Preview app is smaller and faster. (Adam Engst and I are about to release a free minor update to our Take Control of Preview book to update it for macOS 10.15 Catalina.) For creating and manipulating PDFs beyond what Preview can do, we recommend Smile’s PDFpen and PDFpenPro. The main reason to rely on Acrobat Reader is if you regularly run across complex or malformed PDFs that Preview and PDFpen can’t handle.