CVE-2021-34769: Cisco IOS XE

High severity, CVSS 7.5. EPSS: 1.4% chance of exploitation in the next 30 days.

Multiple vulnerabilities in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol processing of Cisco IOS XE Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. These vulnerabilities are due to insufficient validation of CAPWAP packets. An attacker could exploit the vulnerabilities by sending a malformed CAPWAP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition.

Affected products

• Cisco IOS XE: version 3.15.1xbs only; version 3.15.2xbs only; version 17.3.1 only; version 17.3.2 only; version 17.3.2a only; version 17.4.1 only; …

Published 2021-09-23. Last modified 2026-06-17.