CVE-2026-20263: Cisco IOS XE

High severity, CVSS 8.6. EPSS: 0.6% chance of exploitation in the next 30 days.

A vulnerability in the Blocks Extensible Exchange Protocol (BEEP) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling when parsing a specific BEEP SOAP request. An attacker could exploit this vulnerability by sending a specific BEEP SOAP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition.

Affected products

• Cisco IOS XE: version 16.6.2 only; version 16.6.3 only; version 16.6.4 only; version 16.6.4a only; version 16.6.4s only; version 16.6.5 only; …

Published 2026-08-05. Last modified 2026-09-28.