CVE-2026-20152: Cisco Secure Web Appliance

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

A vulnerability in the authentication service feature of Cisco AsyncOS Software for Cisco Secure Web Appliance could allow an unauthenticated, remote attacker to bypass authentication policy requirements. This vulnerability is due to improper validation of user-supplied authentication input in HTTP requests. An attacker could exploit this vulnerability by sending HTTP requests that contain specific authentication requests to an affected device. A successful exploit could allow the attacker to bypass policy enforcement on the device. There is no direct impact to the Cisco Secure Web Appliance. However, as a result of exploiting this vulnerability, an attacker could send HTTP requests that should be restricted through the device.

Affected products

• Cisco Cisco Secure Web Appliance: version 11.8.0-453 only; version 12.5.3-002 only; version 12.0.3-007 only; version 12.0.3-005 only; version 14.1.0-032 only; version 14.1.0-047 only; …

Published 2026-04-15. Last modified 2026-06-17.