CVE-2025-62567 is a medium-severity vulnerability classified under CWE-191 (Integer Underflow) affecting Microsoft Windows 10 Version 1809, specifically build 10.0.17763.0. The vulnerability exists in the Hyper-V virtualization component, where an integer underflow occurs due to improper validation or handling of integer values. This underflow causes wraparound behavior that can lead to unexpected states or resource mismanagement within Hyper-V. An attacker with authorized access but low privileges can exploit this flaw remotely over the network to trigger a denial of service condition, effectively disrupting virtual machine operations or the host's virtualization services. The CVSS 3.1 vector indicates network attack vector (AV:N), high attack complexity (AC:H), low privileges required (PR:L), no user interaction (UI:N), unchanged scope (S:U), no impact on confidentiality or integrity (C:N/I:N), but high impact on availability (A:H). The exploitability is somewhat limited by the high complexity, but the potential for service disruption in virtualized environments is significant. No known exploits have been reported in the wild, and no official patches or mitigations have been published at the time of this report. Organizations running legacy Windows 10 1809 systems with Hyper-V enabled should be aware of this vulnerability and monitor for updates from Microsoft.

For European organizations, the primary impact of CVE-2025-62567 is the potential for denial of service attacks against critical virtualized infrastructure running on Windows 10 Version 1809 with Hyper-V enabled. This can disrupt business operations, especially for enterprises relying on Hyper-V for virtualization of servers, development environments, or cloud services. Availability loss can lead to downtime, impacting productivity and potentially causing financial losses. Since the vulnerability requires network access and low privileges, insider threats or compromised internal systems could exploit it to cause disruption. Confidentiality and integrity are not affected, so data breaches or manipulation are not direct concerns. However, service outages in sectors such as finance, manufacturing, or public services could have cascading effects. The lack of patches increases risk until mitigations or updates are available. Organizations still using Windows 10 1809, despite its age, are particularly vulnerable, as newer Windows versions are not affected.

1. Upgrade affected systems to a supported and patched version of Windows, preferably Windows 10 versions later than 1809 or Windows 11, where this vulnerability is not present. 2. If upgrading is not immediately feasible, disable Hyper-V on Windows 10 Version 1809 systems where virtualization is not essential to eliminate the attack surface. 3. Implement network segmentation and strict access controls to limit which users and systems can access Hyper-V hosts, reducing the risk of exploitation by unauthorized or low-privilege users. 4. Monitor network traffic and system logs for unusual activity related to Hyper-V services that could indicate exploitation attempts. 5. Apply principle of least privilege to all users and services interacting with Hyper-V to minimize potential attack vectors. 6. Stay informed on Microsoft security advisories for patches or workarounds addressing CVE-2025-62567 and deploy them promptly once available. 7. Consider deploying intrusion detection or prevention systems tuned to detect anomalous Hyper-V behavior or known exploit patterns once they emerge. 8. Conduct regular vulnerability assessments and penetration testing focusing on virtualization infrastructure to identify and remediate weaknesses proactively.