CVE-2025-53717 is a vulnerability identified in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0) that affects the Virtualization-Based Security (VBS) Enclave component. The root cause is a reliance on untrusted inputs during a security decision process within the enclave, classified under CWE-807 (Reliance on Untrusted Inputs in a Security Decision). This flaw allows an attacker with authorized local access but low privileges to escalate their privileges by manipulating inputs that the enclave trusts incorrectly. The VBS enclave is designed to provide a secure execution environment isolated from the rest of the operating system, protecting sensitive operations and data. Exploiting this vulnerability could enable an attacker to bypass these protections, gaining elevated privileges that compromise system confidentiality, integrity, and availability. The CVSS v3.1 score of 7.0 reflects a high severity with attack vector local (AV:L), attack complexity high (AC:H), privileges required low (PR:L), no user interaction (UI:N), and impacts rated high on confidentiality, integrity, and availability. No public exploits are known at this time, but the vulnerability is published and should be addressed promptly. The lack of available patches at the time of disclosure requires organizations to implement compensating controls until updates are released.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and government agencies relying on Windows 11 25H2 with VBS enabled for enhanced security. Successful exploitation could lead to unauthorized privilege escalation, allowing attackers to execute code with elevated rights, access sensitive data, or disrupt critical services. This is particularly concerning for sectors such as finance, healthcare, and critical infrastructure where virtualization and enclave technologies are used to protect sensitive workloads. The local attack vector means that insider threats or attackers who have gained limited access could leverage this flaw to deepen their foothold. The high impact on confidentiality, integrity, and availability could result in data breaches, system compromise, and operational disruptions. Given the widespread adoption of Windows 11 across Europe, the threat surface is considerable, and the absence of known exploits does not preclude future active exploitation.

Organizations should prioritize the following mitigation steps: 1) Monitor Microsoft security advisories closely and apply patches or updates as soon as they become available to remediate the vulnerability. 2) Restrict local access to systems running Windows 11 25H2 with VBS enabled, enforcing strict access controls and least privilege principles to minimize the risk of local exploitation. 3) Employ endpoint detection and response (EDR) solutions capable of detecting unusual privilege escalation attempts or suspicious activity within VBS enclaves. 4) Harden system configurations by disabling unnecessary local accounts and services that could be leveraged for initial access. 5) Conduct regular security audits and penetration tests focusing on privilege escalation vectors. 6) Educate system administrators and users about the risks of local privilege escalation and the importance of maintaining updated systems. 7) Consider deploying additional security layers such as application whitelisting and virtualization-based isolation to reduce attack surface.