CVE-2026-65639

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.

  • Published Sep 10, 2026
  • CVSS 9.5 critical
  • 1.4% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-65639 at the National Vulnerability Database