CVE-2025-48807 is a vulnerability identified in Microsoft Windows 10 Version 1809 (build 10.0.17763.0) affecting the Hyper-V virtualization platform. The root cause is an improper restriction of communication channels to intended endpoints (CWE-923), which means that the communication paths within Hyper-V are not adequately confined, allowing an attacker with authorized local access to interact with components or services they should not be able to. This can lead to local code execution with the privileges of the attacker. The vulnerability requires the attacker to have limited privileges (PR:L) and user interaction (UI:R), and the attack complexity is high (AC:H), indicating that exploitation is non-trivial and likely requires specific conditions or user actions. The CVSS v3.1 base score is 6.7, reflecting medium severity with high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). The scope remains unchanged (S:U), meaning the impact is confined to the vulnerable component without affecting other system components. No known exploits have been reported in the wild as of the publication date (August 12, 2025). The vulnerability was reserved in May 2025 and published in August 2025. No patches or updates are linked yet, so mitigation may rely on workarounds or restricting local access until a fix is released.

For European organizations, this vulnerability poses a risk primarily to environments running Windows 10 Version 1809 with Hyper-V enabled. Since Hyper-V is commonly used in enterprise and government sectors for virtualization and testing, exploitation could allow attackers with local access to execute arbitrary code, potentially leading to data breaches, system compromise, or disruption of critical services. The impact on confidentiality, integrity, and availability is high, meaning sensitive data could be exposed or altered, and system operations could be disrupted. However, the requirement for local access and user interaction limits the risk of remote exploitation, reducing the likelihood of widespread automated attacks. Organizations with legacy systems or delayed patching cycles are particularly vulnerable. The absence of known exploits in the wild suggests that immediate exploitation is unlikely but vigilance is necessary. The vulnerability could be leveraged in targeted attacks against high-value assets, especially in sectors such as finance, government, and critical infrastructure within Europe.

1. Prioritize upgrading or patching Windows 10 systems to versions later than 1809 where this vulnerability is addressed once patches become available from Microsoft. 2. Restrict local access to systems running Hyper-V to trusted personnel only, using strong access controls and physical security measures. 3. Disable Hyper-V on systems where virtualization is not required to reduce the attack surface. 4. Monitor logs and system behavior for unusual Hyper-V communication channel activity or unauthorized local code execution attempts. 5. Implement application whitelisting and endpoint detection and response (EDR) solutions to detect and block suspicious local activities. 6. Educate users about the risks of interacting with untrusted content or applications that could trigger the required user interaction for exploitation. 7. Maintain an inventory of systems running Windows 10 Version 1809 and plan for timely upgrades or replacements to supported versions. 8. Use network segmentation to isolate critical systems and limit lateral movement in case of compromise.