CVE-2026-111231

Netgate pfSense CE through 2.9.0 contains an authorization bypass vulnerability that allows read-only WebGUI users to replace config.xml because config_restore() and config_install() ignore the 'User - Config: Deny Config Write' privilege. Attackers holding page privileges for services_acb.php, uploadconfig.php, diag_confbak.php, or diag_backup.php can install a chosen config.xml to gain root-level code execution after reload or reboot.

• https://abraxaslabs.tech/research/pfsense-ce-leftovers
• https://github.com/abraxas/pfsense-config-readonly-restore
• https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/config.lib.inc#L588-L597
• https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a333180425ce7719070f95f9/src/etc/inc/config.lib.inc#L743-L798
• https://www.vulncheck.com/advisories/netgate-pfsense-ce-through-2.9.0-authorization-bypass-via-config-restore-and-config-install