CVE-2026-25938 is an authentication bypass vulnerability identified in frangoteam's FUXA software versions 1.2.8 through 1.2.10. FUXA is a web-based process visualization tool commonly used in SCADA, HMI, and dashboard applications to monitor and control industrial processes. The vulnerability arises when the Node-RED plugin is enabled, which introduces a flaw in the authentication mechanism allowing an unauthenticated remote attacker to bypass authentication controls. This bypass enables the attacker to execute arbitrary code on the server hosting FUXA, effectively gaining full control over the system. The root cause relates to improper authentication validation (CWE-290) and missing authentication for critical functionality (CWE-306). The vulnerability is remotely exploitable without any user interaction or privileges, making it highly dangerous. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (VC:H, VI:H, VA:H). Although no public exploits have been reported yet, the critical severity and ease of exploitation make this a high-priority threat. The vendor has addressed the issue in FUXA version 1.2.11, and users are strongly advised to upgrade. The vulnerability poses a significant risk to industrial environments relying on FUXA for process visualization and control, as compromise could lead to operational disruption, data theft, or sabotage.

For European organizations, especially those in critical infrastructure sectors such as manufacturing, energy, water treatment, and transportation that utilize SCADA/HMI systems, this vulnerability presents a severe risk. Exploitation could lead to unauthorized control over industrial processes, resulting in operational downtime, physical damage to equipment, safety hazards, and loss of sensitive operational data. The ability to execute arbitrary code remotely without authentication means attackers could deploy ransomware, sabotage operations, or conduct espionage. Given the increasing digitization and automation in European industries, the impact could extend beyond individual organizations to affect supply chains and national infrastructure resilience. The vulnerability also raises compliance concerns under regulations like NIS2 and GDPR if data confidentiality or service availability is compromised. The lack of known exploits in the wild currently reduces immediate risk but does not diminish the urgency for remediation due to the high severity and potential impact.

1. Immediately upgrade all FUXA installations to version 1.2.11 or later, where the vulnerability is patched. 2. If upgrading is not immediately feasible, disable the Node-RED plugin to prevent exploitation, as the vulnerability is contingent on this plugin being enabled. 3. Implement network segmentation to isolate SCADA/HMI systems from general IT networks and restrict access to trusted administrators only. 4. Employ strict firewall rules and intrusion detection/prevention systems to monitor and block unauthorized access attempts to FUXA servers. 5. Conduct thorough audits of existing FUXA deployments to identify affected versions and plugin configurations. 6. Establish continuous monitoring for anomalous activities indicative of exploitation attempts, such as unexpected code execution or unauthorized access patterns. 7. Review and enhance authentication and access control policies around industrial control systems to minimize exposure. 8. Coordinate with vendors and cybersecurity authorities to stay informed about any emerging exploit techniques or additional patches. 9. Train operational technology (OT) and IT security teams on the specifics of this vulnerability and response procedures. 10. Develop and test incident response plans tailored to potential compromises of SCADA/HMI environments.