CVE-2026-67402
CriticalCVSS 9.2Exploitation Probability (EPSS)
Low risk25th percentile - higher than 25% of all known CVEs
Summary
An insecure Apache configuration in ConfigServer Security & Firewall maps /usr/bin as CGI programs through the Messenger v3 HTTPS virtual host. A remote unauthenticated attacker whose address is blocked can request a mapped executable and run arbitrary commands as the Apache user. The vulnerability affects installations where CSF Messenger v3 and its HTTPS mode are enabled. WebPros addressed the vulnerability in version 16.31.
Risk Assessment
An attacker can bypass IP blocking and execute arbitrary commands on the server, potentially leading to full system compromise.
Recommendation
Update ConfigServer Security & Firewall to version 16.31 or later and review Apache configuration for insecure CGI mappings.
Other vulnerabilities in ConfigServer Security & Firewall
See all- CVE-2026-65639Critical
OS command injection in the advanced-rule parser of ConfigServer Security & Firewall allows a remote attacker who controls a configured allow/deny feed to execute arbitrary commands as root, due to insufficient validation of feed-supplied rule data. 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.
- CVE-2026-65638Critical
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.
Original NVD description (English source)
An insecure Apache configuration in ConfigServer Security & Firewall maps /usr/bin as CGI programs through the Messenger v3 HTTPS virtual host. A remote unauthenticated attacker whose address is blocked can request a mapped executable and run arbitrary commands as the Apache user. The vulnerability affects installations where CSF Messenger v3 and its HTTPS mode are enabled. WebPros addressed the vulnerability in version 16.31.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS