CISCO: Reference: 🔗 Cisco Security Advisory — Cisco ISE Cross-Site Scripting Vulnerability

CISCO Security Advisory

Published Date: Not specified

CVE: CVE-2026-20309

Advisory Summary

🗓️ 16 Sep 2026

💡 ➤ Cisco ISE Reflected XSS: Medium-Risk Web Interface Exposure
Cisco disclosed a vulnerability in the web-based management interface of Cisco Identity Services Engine (ISE) that could enable an unauthenticated remote attacker to trigger a reflected cross-site scripting (XSS) attack against an authenticated user of the interface.

• An attacker can craft a malicious link and social-engineer a user into clicking it.
• If successful, the attacker may be able to execute arbitrary script in the browser context of the affected ISE interface.
• Potential outcomes include access to sensitive browser-based information.

• The management UI does not properly validate user-supplied input, enabling injection into the rendered response.

• Cisco has released software updates to address the issue.
• No workarounds are provided—patching is the primary mitigation.

• Reduce exposure of the ISE admin interface (network ACLs / restricted management access).
• Apply browser hardening and limit access to trusted users only.
• Monitor for suspicious inbound requests/URL patterns targeting the ISE web UI.

• CVE: CVE-2026-20309
• Security Impact Rating: Medium

Reference: Vendor Advisory