A vulnerability in the Flexible NetFlow Version 9 packet processor of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers and Cisco AireOS Software for Cisco Wireless LAN Controllers (WLC) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of certain parameters in a Flexible NetFlow Version 9 record. An attacker could exploit this vulnerability by spoofing the address of an existing Access Point on the network and sending a Control and Provisioning of Wireless Access Points (CAPWAP) packet that includes a crafted Flexible NetFlow Version 9 record to an affected device. A successful exploit could allow the attacker to cause a process crash that would lead to a reload of the device.