CVE-2025-48811 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) that stems from a missing support for integrity checks within the Windows Virtualization-Based Security (VBS) Enclave. VBS enclaves are designed to provide a secure execution environment isolated from the rest of the operating system, protecting sensitive operations and data from tampering or unauthorized access. The absence of proper integrity verification in this enclave allows an authorized attacker—someone with existing local privileges—to elevate their privileges further within the system. This vulnerability is classified under CWE-353, which relates to missing support for integrity checks, indicating that the system fails to verify the integrity of critical components or data, thereby enabling potential manipulation or unauthorized escalation. The CVSS 3.1 base score of 6.7 (medium severity) reflects that exploitation requires local access with high privileges but no user interaction, and can lead to high impact on confidentiality, integrity, and availability. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk because it undermines the security guarantees of VBS, a core security feature in Windows 10 aimed at protecting against sophisticated attacks. Since Windows 10 Version 1809 is an older release, systems still running this version remain vulnerable until patched or upgraded.

For European organizations, this vulnerability presents a tangible risk, especially for enterprises and government agencies that rely on Windows 10 Version 1809 in their infrastructure. The ability for an authorized local user to escalate privileges can lead to unauthorized access to sensitive data, disruption of critical services, and potential lateral movement within networks. This is particularly concerning for sectors with stringent data protection requirements such as finance, healthcare, and public administration, where confidentiality and integrity are paramount. The compromise of VBS undermines trust in hardware-backed security features, potentially exposing cryptographic keys, credentials, or other protected assets. Additionally, organizations that have not migrated to newer Windows versions or have legacy systems in place are at greater risk. The absence of known exploits in the wild currently reduces immediate threat levels, but the medium severity score and the nature of the vulnerability warrant proactive mitigation to prevent future exploitation attempts.

Given the lack of an official patch at the time of this report, European organizations should prioritize the following mitigations: 1) Upgrade affected systems from Windows 10 Version 1809 to a supported and updated Windows version where this vulnerability is addressed, as newer versions include improved VBS integrity checks. 2) Restrict local administrative privileges strictly, employing the principle of least privilege to minimize the pool of users who could exploit this vulnerability. 3) Implement robust endpoint detection and response (EDR) solutions capable of monitoring for unusual privilege escalation activities within local environments. 4) Enforce strong access controls and multi-factor authentication for local accounts to reduce the risk of unauthorized access. 5) Regularly audit and inventory systems to identify any running the vulnerable Windows 10 1809 build and prioritize their remediation. 6) Monitor security advisories from Microsoft for the release of patches or workarounds and apply them promptly once available. 7) Consider deploying application control policies and virtualization-based security features that can limit the impact of privilege escalation attempts.