Netgate pfSense CE 2.4.5 through 2.9.0 OS Command Injection via system_advanced_admin.php

Advisories

Netgate pfSense CE 2.4.5 through 2.9.0 OS Command Injection via system_advanced_admin.php

Severity: high
Date: 10/15/2026
Affecting: pfSense CE >= 2.4.5, <= 2.9.0
CVE: CVE-2026-111226
CWE: CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVSS: 8.6
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References: https://github.com/abraxas/pfsense-sshguard-crlf
https://abraxaslabs.tech/research/pfsense-ce-leftovers
https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/usr/local/pfSense/include/www/system_advanced_admin.inc#L355-L381
https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/syslog.inc#L531-L563
Credit: Abraxas Labs
Description: pfSense CE 2.4.5 through 2.9.0 contains an OS command injection vulnerability that allows authenticated WebGUI users with Advanced Admin Access privilege to execute commands as root via Login Protection settings. Attackers can submit sshguard threshold, block time, or detection time values containing newlines or $(...) that are written unvalidated to sshguard.conf and sourced as root on restart.

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