CVE-2025-20240: Cisco IOS XE Software

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

A vulnerability in the Web Authentication feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to conduct a reflected cross-site scripting attack (XSS) on an affected device. This vulnerability is due to improper sanitization of user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a malicious link. A successful exploit could allow the attacker to execute a reflected XSS attack and steal user cookies from the affected device.

Affected products

• Cisco Cisco IOS XE Software: version 16.6.1 only; version 16.6.2 only; version 16.6.3 only; version 16.6.4 only; version 16.6.5 only; version 16.6.4a only; …

Published 2025-09-24. Last modified 2026-09-26.