An information disclosure vulnerability exists when Microsoft Edge PDF Reader improperly handles objects in memory. An attacker who successfully exploited the vulnerability could obtain information to further compromise the users system. To exploit the vulnerability, in a web-based attack scenario, an attacker could host a website that contains malicious PDF content. In addition, compromised websites and websites that accept or host user-provided content could contain specially crafted PDF content that could exploit the vulnerability. However, in all cases an attacker would have no way to force a user to view the attacker-controlled content. Instead, an attacker would have to convince a user to take action. For example, an attacker could trick a user into clicking a link that takes the user to the attacker's site. The security update addresses the vulnerability by modifying how Microsoft Edge PDF Reader handles objects in memory.