Adobe Digital Editions versions 4.5.2 and earlier has an important vulnerability that could lead to memory address leak.
https://helpx.adobe.com/security/products/Digital-Editions/apsb16-45.html
https://euvd.enisa.europa.eu/vulnerability/EUVD-2016-8737
http://www.zerodayinitiative.com/advisories/ZDI-16-636