CVE-2016-9221: A Denial of Service Vulnerability in 802.11 ingress connection authentication handling for the Cisco Mobili...

Security readout for executives and security teams

This flaw can let a nearby unauthenticated attacker disrupt Wi-Fi authentication on certain Cisco Mobility Express 2800 and 3800 access points in a specific configuration. It is not an internet-reachable issue; the attacker must be adjacent to the wireless network. The business impact is failed client authentication and possible Wi-Fi service disruption in affected areas. Exposure is limited to organizations using Cisco Mobility Express 2800 or 3800 access points in local mode with 40 MHz on affected software releases. Internet-facing asset scans will not reliably identify exposure because exploitation requires wireless adjacency. Treat this as a targeted availability risk for wireless environments, not a broad enterprise compromise issue. Patch affected APs where Wi-Fi uptime matters, especially offices, campuses, and operational locations that depend on wireless authentication. Mitigation focus: Upgrade affected access points to a Cisco-listed fixed release.; Prioritize sites where Wi-Fi availability is business-critical.; Review Cisco advisory cisco-sa-20170118-cme2 and bug CSCvb33575..

Prepared

Jun 13, 2026, 12:51 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.