CVE-2026-25939 is an authorization bypass vulnerability classified under CWE-862 affecting frangoteam's FUXA software versions prior to 1.2.11. FUXA is a web-based process visualization tool commonly used in SCADA, HMI, and dashboard environments to monitor and control industrial processes. The vulnerability allows an unauthenticated, remote attacker to bypass authorization controls and create or modify schedulers arbitrarily. Schedulers in FUXA typically automate tasks or control sequences in ICS/SCADA environments, so unauthorized manipulation can lead to unauthorized command execution or disruption of industrial processes. The vulnerability does not require any authentication or user interaction, making exploitation straightforward over the network. The CVSS 4.0 vector (AV:N/AC:L/AT:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H) reflects network attack vector, low complexity, no privileges or user interaction required, and high impact on integrity and availability with scope change. Although no public exploits have been reported yet, the critical nature of the flaw and the sensitive environments where FUXA is deployed make it a significant threat. The vendor has addressed the issue in version 1.2.11, and users are strongly advised to upgrade. The vulnerability exposes ICS/SCADA environments to potential follow-on attacks that could disrupt industrial operations or cause safety hazards.

For European organizations, this vulnerability poses a severe risk to industrial control systems, particularly in sectors such as energy, manufacturing, transportation, and utilities that rely on SCADA/HMI solutions like FUXA. Exploitation could lead to unauthorized manipulation of industrial processes, causing operational disruptions, safety incidents, or damage to physical infrastructure. The integrity and availability of critical systems could be compromised, potentially leading to production downtime, financial losses, and regulatory penalties under frameworks like NIS2 and GDPR if personal or operational data is affected. The lack of authentication requirement increases the likelihood of exploitation by remote attackers, including nation-state actors or cybercriminal groups targeting critical infrastructure. The potential for follow-on actions means attackers could pivot to other parts of the network or deploy ransomware or sabotage attacks. Given the strategic importance of ICS in Europe’s industrial base and critical infrastructure, the impact could be widespread and severe without timely mitigation.

1. Immediate upgrade of all FUXA installations to version 1.2.11 or later to apply the official patch addressing the authorization bypass. 2. Implement strict network segmentation to isolate ICS/SCADA environments from general IT networks and the internet, reducing exposure to remote attacks. 3. Deploy intrusion detection and prevention systems (IDS/IPS) with signatures or behavioral rules to detect anomalous scheduler creation or modification activities within FUXA. 4. Enforce strong access controls and multi-factor authentication on management interfaces to limit potential attack vectors beyond this vulnerability. 5. Conduct regular audits of scheduler configurations and logs to identify unauthorized changes promptly. 6. Establish incident response plans specific to ICS/SCADA environments to quickly contain and remediate any exploitation attempts. 7. Monitor threat intelligence sources for emerging exploits or indicators of compromise related to CVE-2026-25939. 8. Engage with vendors and cybersecurity communities for updates and best practices tailored to FUXA and industrial control systems security.