A vulnerability in the Event Management Service daemon (emsd) of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of gRPC requests. An attacker could exploit this vulnerability by repeatedly sending unauthenticated gRPC requests to the affected device. A successful exploit could cause the emsd process to crash, resulting in a DoS condition. Resolved in Cisco IOS XR 6.5.1 and later.