CVE-2026-20309: Cisco Identity Services Engine Software

Medium severity, CVSS 6.1. EPSS: 0.2% chance of exploitation in the next 30 days.

A vulnerability in the web-based management interface of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to conduct a reflected cross-site scripting (XSS) attack against a user of the interface. This vulnerability exists because the web-based management interface does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

Affected products

• Cisco Cisco Identity Services Engine Software: version 3.1.0 only; version 3.1.0 p1 only; version 3.1.0 p3 only; version 3.1.0 p2 only; version 3.2.0 only; version 3.1.0 p4 only; …

Published 2026-09-16. Last modified 2026-09-18.