CVE-2025-64121 is an authentication bypass vulnerability classified under CWE-288 affecting Nuvation Energy's Multi-Stack Controller (MSC) versions 2.3.8 through before 2.5.1. The vulnerability arises because the MSC allows authentication to be circumvented via an alternate path or communication channel, effectively enabling an attacker to gain unauthorized access without valid credentials or any user interaction. The vulnerability is remotely exploitable over the network (AV:N), requires no privileges (PR:N), and no user interaction (UI:N), making it highly accessible to attackers. The CVSS 4.0 vector indicates high impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H), and the scope is partially changed (S:P), meaning the vulnerability affects resources beyond the initially vulnerable component. The MSC is a critical component in energy management systems, controlling stacks of energy storage or generation units. Unauthorized access could allow attackers to manipulate energy flows, disrupt power delivery, or cause physical damage to infrastructure. No patches are currently linked, and no public exploits are known, but the critical severity score demands urgent attention. The vulnerability was reserved in late 2025 and published in early 2026, indicating recent discovery and disclosure. The MSC's role in energy infrastructure makes this vulnerability a high-value target for threat actors aiming at industrial control systems or critical infrastructure.

For European organizations, the impact of CVE-2025-64121 is substantial due to the increasing reliance on renewable energy systems and smart grid technologies that utilize Nuvation Energy's MSC devices. Successful exploitation could lead to unauthorized control over energy stacks, resulting in potential power outages, manipulation of energy distribution, or damage to physical assets. This could disrupt critical services, cause financial losses, and undermine trust in energy providers. Additionally, the breach of confidentiality could expose sensitive operational data, while integrity violations could lead to incorrect energy management decisions. Availability impacts could cause downtime in energy supply, affecting both industrial and residential consumers. Given Europe's commitment to green energy and smart infrastructure, this vulnerability poses a direct threat to energy security and operational continuity. The lack of authentication requirements and ease of exploitation increase the likelihood of attacks, including from nation-state actors or cybercriminals targeting critical infrastructure.

European organizations should immediately identify all Nuvation Energy MSC devices running affected versions (2.3.8 up to before 2.5.1) and prioritize their remediation. Since no official patches are currently linked, organizations should engage with Nuvation Energy for updates or workarounds. In the interim, network segmentation should be enforced to isolate MSC devices from untrusted networks and limit exposure to potential attackers. Implement strict access controls and monitoring on the management interfaces of MSC devices, including logging and alerting on anomalous authentication attempts or unusual communication channels. Employ network intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation attempts targeting authentication bypass techniques. Regularly audit device configurations to ensure no alternate or undocumented access paths exist. Consider deploying compensating controls such as multi-factor authentication on any upstream systems controlling MSC access. Finally, develop and test incident response plans specifically for energy management system compromises to reduce recovery time and impact.