CVE-2025-48822 is a high-severity vulnerability identified as an out-of-bounds read (CWE-125) in the Windows Hyper-V component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability allows an unauthorized local attacker to execute arbitrary code on the affected system. The flaw arises due to improper bounds checking in Hyper-V, which leads to reading memory outside the intended buffer limits. Exploiting this vulnerability requires local access and user interaction, but no privileges are needed initially (PR:N). The vulnerability affects confidentiality, integrity, and availability with a scope change (S:C), meaning the attacker can potentially escape from a virtualized environment or sandbox to execute code on the host system. The CVSS v3.1 base score is 8.6, reflecting the high impact and relatively low attack complexity (AC:L). Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk due to the critical role of Hyper-V in virtualization and cloud environments. Since Windows 10 Version 1809 is an older release, many organizations may still be running this version in legacy environments, increasing exposure. The absence of a patch link suggests that a fix may not yet be publicly available or is pending release, emphasizing the need for immediate mitigation and monitoring.

For European organizations, the impact of CVE-2025-48822 can be substantial, especially for enterprises relying on Windows 10 Version 1809 in virtualized environments. Hyper-V is widely used for server virtualization, development, and testing. Exploitation could allow attackers to escape virtual machines, compromise host systems, and gain elevated privileges, leading to data breaches, disruption of critical services, and potential lateral movement within networks. Confidentiality is at high risk as attackers may access sensitive data residing on host machines. Integrity and availability are also threatened, as attackers could modify system files or cause system crashes. Sectors such as finance, healthcare, government, and critical infrastructure in Europe that rely on virtualization for operational continuity are particularly vulnerable. The requirement for local access and user interaction limits remote exploitation but does not eliminate risk, especially in environments with shared access or insider threats. The lack of known exploits currently provides a window for proactive defense but also means organizations must act before attackers develop weaponized code.

Given the absence of an official patch, European organizations should implement specific mitigations beyond generic advice: 1) Upgrade affected systems to a supported and patched Windows version where this vulnerability is resolved, prioritizing migration away from Windows 10 Version 1809. 2) Restrict local access to systems running vulnerable Hyper-V instances by enforcing strict access controls, including multi-factor authentication and least privilege principles. 3) Disable or limit Hyper-V usage on endpoints where virtualization is not essential to reduce the attack surface. 4) Monitor logs and system behavior for unusual activity indicative of exploitation attempts, focusing on Hyper-V related events and memory access anomalies. 5) Employ application whitelisting and endpoint detection and response (EDR) solutions capable of detecting suspicious local code execution and memory exploitation techniques. 6) Educate users about the risks of executing untrusted code or interacting with unknown files to reduce the likelihood of user interaction-based exploitation. 7) Isolate legacy systems running Windows 10 Version 1809 from critical network segments to contain potential compromises.