CVE-2026-65638: Configserver Security & Firewall

Critical severity, CVSS 9.2. EPSS: 2.3% chance of exploitation in the next 30 days.

Improper escaping of a request URL in ConfigServer Security & Firewall allows an unauthenticated remote attacker to execute arbitrary commands as the CSF service account via shell command injection. The vulnerability affects versions of the software originally distributed by ConfigServer, as well as versions of the WebPros-maintained fork that contain the vulnerable code. WebPros has addressed the vulnerability in version 16.30. Other forks or independently maintained versions of ConfigServer Security & Firewall (CSF) may also be affected and should be evaluated independently.

Affected products

• Configserver Configserver Security & Firewall: from 14.00
• WebPros Configserver Security & Firewall: from 14.00, before 16.30 (fixed in 16.30)

Published 2026-09-10. Last modified 2026-09-10.