CVE-2026-25752 Overview
CVE-2026-25752 is a critical authorization bypass vulnerability in FUXA, a web-based Process Visualization (SCADA/HMI/Dashboard) software. The vulnerability allows an unauthenticated, remote attacker to modify device tags via WebSockets, bypassing role-based access controls. This flaw enables attackers to overwrite arbitrary device tags or disable communication drivers, exposing connected ICS/SCADA environments to potentially dangerous follow-on actions.
Critical Impact
Unauthenticated remote attackers can manipulate physical processes and disconnect devices from the HMI interface, potentially causing operational disruption in industrial control systems.
Affected Products
- FUXA through version 1.2.9
- Frangoteam FUXA web-based SCADA/HMI software
- All FUXA deployments with WebSocket endpoints accessible from untrusted networks
Discovery Timeline
- February 6, 2026 - CVE-2026-25752 published to NVD
- February 10, 2026 - Last updated in NVD database
Technical Details for CVE-2026-25752
Vulnerability Analysis
The vulnerability stems from missing authorization checks (CWE-862) in the WebSocket message handling functionality of FUXA. When processing incoming WebSocket requests for device tag modifications, the application fails to verify that the requesting client has appropriate authentication credentials or role-based permissions.
This architectural flaw allows any network-connected attacker to send specially crafted WebSocket messages directly to the FUXA server, bypassing the intended access control mechanisms entirely. The impact is particularly severe in ICS/SCADA environments where FUXA serves as the Human-Machine Interface (HMI) for monitoring and controlling industrial processes.
Root Cause
The root cause is the absence of authorization enforcement on WebSocket endpoints responsible for device tag manipulation. FUXA's WebSocket implementation accepts and processes commands to modify device tags without validating the identity or permissions of the requesting party. This represents a fundamental design flaw where security-critical operations are exposed without proper access controls.
Attack Vector
The attack vector is network-based and requires no authentication or user interaction. An attacker with network access to the FUXA WebSocket endpoint can exploit this vulnerability remotely.
The attack proceeds as follows: the attacker establishes a WebSocket connection to the FUXA server, then sends crafted messages to modify device tags or disable communication drivers. Because no authentication check occurs, these commands are processed as if they came from an authorized administrator. The attacker can thereby manipulate process values, disable drivers controlling physical equipment, or otherwise disrupt operations in connected ICS/SCADA environments.
The exploitation method involves establishing a WebSocket connection to the vulnerable FUXA server and sending tag modification requests without providing valid credentials. The server processes these requests due to the missing authorization checks, allowing arbitrary device tag manipulation. For detailed technical information, refer to the GitHub Security Advisory GHSA-ggxw-g3cp-mgf8.
Detection Methods for CVE-2026-25752
Indicators of Compromise
- Unexpected WebSocket connections from external or untrusted IP addresses to the FUXA server
- Unexplained modifications to device tag values or configurations
- Communication driver disconnections without administrative action
- Anomalous WebSocket traffic patterns indicating automated tag manipulation attempts
Detection Strategies
- Monitor WebSocket connections to FUXA servers for unauthenticated requests attempting tag modifications
- Implement network-level logging to capture all WebSocket traffic to FUXA endpoints
- Deploy intrusion detection rules to identify suspicious patterns in SCADA/HMI WebSocket communications
- Correlate HMI changes with authentication logs to detect unauthorized modifications
Monitoring Recommendations
- Enable comprehensive logging on FUXA servers to track all device tag changes
- Implement alerting for WebSocket connections originating from outside trusted network segments
- Regularly audit device tag values and communication driver states for unexpected changes
- Monitor for unusual WebSocket message volumes that may indicate exploitation attempts
How to Mitigate CVE-2026-25752
Immediate Actions Required
- Upgrade FUXA to version 1.2.10 or later immediately
- Restrict network access to FUXA WebSocket endpoints to trusted sources only
- Implement network segmentation to isolate ICS/SCADA systems from untrusted networks
- Review audit logs for any evidence of unauthorized tag modifications prior to patching
Patch Information
Frangoteam has released FUXA version 1.2.10 which addresses this authorization bypass vulnerability. The patch implements proper authentication and authorization checks on WebSocket endpoints to prevent unauthenticated access. Organizations should upgrade to this version as the primary remediation action. The patched release is available from the GitHub FUXA Release v1.2.10.
Workarounds
- Place FUXA servers behind a reverse proxy that enforces authentication for all WebSocket connections
- Implement firewall rules to restrict WebSocket access to authorized management workstations only
- Deploy network segmentation to prevent untrusted networks from reaching FUXA endpoints
- Consider disabling WebSocket functionality if not operationally required until patching is complete
# Example firewall rule to restrict WebSocket access (iptables)
# Allow WebSocket connections only from trusted management subnet
iptables -A INPUT -p tcp --dport 1881 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 1881 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
