CVE-2025-54091 is an integer overflow or wraparound vulnerability identified in the Hyper-V virtualization component of Microsoft Windows 10 Version 1507 (build 10240). The flaw arises from improper handling of integer values within Hyper-V, leading to an overflow condition that can be exploited by an authorized local attacker to escalate privileges. Specifically, the attacker must have some level of local privileges (PR:L) but does not require user interaction (UI:N). The vulnerability impacts confidentiality, integrity, and availability (C:H/I:H/A:H), meaning a successful exploit could allow the attacker to gain elevated system privileges, potentially compromising the entire host system and any virtual machines running on it. The attack vector is local (AV:L), and the attack complexity is low (AC:L), indicating that exploitation does not require sophisticated conditions. The vulnerability is unpatched as of the publication date, and no known exploits are currently in the wild. Given that Windows 10 Version 1507 is an early release version, many organizations may have upgraded, but legacy systems remain vulnerable. The vulnerability is tracked under CWE-190 (Integer Overflow or Wraparound), a common weakness that can lead to memory corruption and security breaches if not properly mitigated.

The impact of CVE-2025-54091 is significant for organizations still operating Windows 10 Version 1507 with Hyper-V enabled. Successful exploitation allows local attackers to elevate privileges, potentially gaining SYSTEM-level access. This can lead to full control over the host operating system, enabling data theft, system manipulation, deployment of malware, or disruption of services. Virtual machines hosted on the compromised Hyper-V instance may also be at risk, potentially allowing attackers to escape guest isolation boundaries. Organizations relying on legacy Windows 10 systems for critical infrastructure or virtualization workloads face increased risk of insider threats or attacks from compromised local accounts. The lack of public exploits reduces immediate risk but also means defenders must proactively patch or mitigate before exploitation occurs. The vulnerability undermines trust in virtualization security and can have cascading effects on enterprise environments, especially those with sensitive data or regulatory compliance requirements.

To mitigate CVE-2025-54091, organizations should prioritize upgrading affected systems to a supported and patched version of Windows 10 or later, as Windows 10 Version 1507 is outdated and no longer supported by Microsoft. If upgrading is not immediately feasible, restrict local access to systems running this version, ensuring only trusted and authorized personnel have login privileges. Disable Hyper-V if virtualization is not required, reducing the attack surface. Employ strict access controls and monitoring on systems with Hyper-V enabled to detect suspicious privilege escalation attempts. Use endpoint detection and response (EDR) tools to monitor for anomalous behavior indicative of exploitation. Regularly audit local user accounts and privileges to minimize the number of users with elevated rights. Stay informed on Microsoft security advisories for any forthcoming patches or workarounds related to this vulnerability. Finally, implement network segmentation to isolate legacy systems from critical infrastructure to limit potential lateral movement.