A denial of service vulnerability exists in Skype for Business. An attacker who successfully exploited the vulnerability could cause Skype for Business to stop responding. Note that the denial of service would not allow an attacker to execute code or to elevate the attacker's user rights. For an attack to be successful, this vulnerability requires that a user sends a number of emojis in the affected version of Skype for Business. The security update addresses the vulnerability by correcting how Skype for Business handles emojis.