CVE-2025-26633 is a vulnerability classified under CWE-707 (Improper Neutralization) affecting Microsoft Management Console (MMC) in Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability arises from improper neutralization of inputs or commands within MMC, which is a core Windows component used for system administration. This flaw enables an unauthorized local attacker to bypass security features, potentially escalating privileges or executing unauthorized actions. The CVSS v3.1 score is 7.0 (high), reflecting that exploitation requires local access (AV:L), high attack complexity (AC:H), no privileges required (PR:N), and user interaction (UI:R). The impact on confidentiality, integrity, and availability is high, indicating that successful exploitation could lead to full system compromise. No public exploits are known, and no patches have been linked yet, though the vulnerability was published on March 11, 2025. The vulnerability's presence in an older Windows 10 version, which is often still used in enterprise environments for compatibility reasons, increases risk. The improper neutralization likely involves failure to sanitize or validate inputs or commands within MMC, allowing attackers to bypass security controls designed to restrict unauthorized actions.

For European organizations, this vulnerability poses a significant threat, especially to those still operating legacy Windows 10 Version 1809 systems. Successful exploitation could lead to unauthorized privilege escalation, data breaches, and disruption of critical services. Sectors such as government, finance, healthcare, and industrial control systems that rely on MMC for system management are particularly at risk. The local access requirement limits remote exploitation but insider threats or attackers with initial footholds could leverage this flaw to deepen compromise. The high impact on confidentiality, integrity, and availability means sensitive data could be exposed or altered, and system operations disrupted, potentially causing regulatory compliance issues under GDPR and other frameworks. The lack of known exploits provides a window for proactive mitigation but also means organizations should not underestimate the risk once exploit code becomes available.

Organizations should prioritize upgrading from Windows 10 Version 1809 to a supported and patched Windows version to eliminate exposure. Until upgrades are feasible, restrict local access to systems running this version, especially limiting MMC usage to trusted administrators. Implement strict access controls and monitoring on endpoints to detect suspicious MMC activity. Employ application whitelisting and endpoint detection and response (EDR) solutions to identify and block attempts to exploit MMC. Regularly audit user privileges and remove unnecessary local accounts to reduce attack surface. If any patches or workarounds become available from Microsoft, apply them promptly. Additionally, educate users about the risks of executing untrusted actions requiring user interaction to mitigate exploitation vectors. Network segmentation can also limit lateral movement if compromise occurs.