Authorization Bypass Vulnerability in Netgate pfSense CE
CVE-2026-111231

8.6HIGH

Key Information:

Vendor

Netgate

Status
Pfsense Ce
Vendor
CVE Published:
15 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-111231?

Netgate pfSense CE through version 2.9.0 is susceptible to an authorization bypass that enables read-only WebGUI users to manipulate the config.xml file. This occurs due to the negligence of 'User - Config: Deny Config Write' privilege within the config_restore() and config_install() functions. If attackers gain access to specific privileges on services_acb.php, uploadconfig.php, diag_confbak.php, or diag_backup.php, they can replace the existing config.xml file, potentially leading to root-level code execution upon reload or reboot.

Affected Version(s)

pfSense CE 0 <= 2.9.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-111231 - Proof of Concept

References

https://github.com/abraxas/pfsense-config-readonly-restore
exploittechnical-description
https://abraxaslabs.tech/research/pfsense-ce-leftovers
technical-description
https://github.com/pfsense/pfsense/blob/9363ac5b8651a1c7a...
technical-description

CVSS V4

Score:
8.6
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Abraxas Labs
.