CVE-2026-26352: Smoothwall Express

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

Smoothwall Express versions prior to 3.1 Update 13 contain a stored cross-site scripting vulnerability in the /cgi-bin/vpnmain.cgi script due to improper sanitation of the VPN_IP parameter. Authenticated attackers can inject arbitrary JavaScript through VPN configuration settings that executes when the affected page is viewed by other users.

Affected products

• Smoothwall Smoothwall Express: up to and including 3.0; version 3.1 only

Published 2026-03-30. Last modified 2026-06-17.