CVE-2026-65639

Critical

Description

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.

SeverityCritical

CVSS9.5

Exploit probability—

ProductConfigServer Security & Firewall

PublishedSep 10, 2026

First seenSep 10, 2026

Weakness typeCWE-78OS command injection

How to fix

Update

WebPros ConfigServer Security & Firewall16.30 or later

Affected products

Product	Affected versions	Fixed in
WebPros ConfigServer Security & Firewall	2.15 ≤ v < 16.30	16.30
ConfigServer ConfigServer Security & Firewall	2.15	—

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