CVE-2026-20178: Cisco Webex Web App

Medium severity, CVSS 4.3. EPSS: 0.2% chance of exploitation in the next 30 days.

A vulnerability in the browser-based version of Cisco Webex App could have allowed an unauthenticated, remote attacker to redirect users to a malicious webpage. Cisco has addressed this vulnerability in the Cisco Webex App, and no customer action is needed. This vulnerability existed due to improper input validation of URL parameters in an HTTP request. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by persuading a user to click a crafted URL. A successful exploit could have allowed the attacker to redirect a user to a malicious website.

Affected products

• Cisco Webex Web App: affected versions not specified

Published 2026-06-17. Last modified 2026-06-22.