CVE-2025-48002 is a medium-severity vulnerability identified in Microsoft Windows Server 2025, specifically affecting the Server Core installation version 10.0.26100.0. The vulnerability arises from an integer overflow or wraparound issue within the Windows Hyper-V component. Integer overflow (CWE-190) occurs when an arithmetic operation attempts to create a numeric value that is outside the range that can be represented with a given number of bits, causing the value to wrap around unexpectedly. In this case, the flaw allows an authorized attacker—meaning one with some level of legitimate access—to exploit the vulnerability to disclose sensitive information over an adjacent network. The attack vector is adjacent network (AV:A), indicating the attacker must be on the same local network segment or have network adjacency to the target system. The attack complexity is low (AC:L), and the attacker requires low privileges (PR:L) but no user interaction (UI:N) is needed. The scope is unchanged (S:U), meaning the vulnerability affects resources within the same security scope. The impact is primarily on confidentiality (C:H), with no impact on integrity or availability. This suggests that the attacker can extract sensitive data but cannot modify or disrupt system operations. No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that mitigation may rely on vendor updates once available. The vulnerability is classified under CWE-190 (Integer Overflow) and also tagged with CWE-125 (Out-of-bounds Read), suggesting that the overflow may lead to reading memory outside intended bounds, facilitating information disclosure. The vulnerability affects Windows Server 2025 Server Core installations, a minimalistic installation option designed for running Hyper-V and other server roles with reduced overhead and attack surface. Given the involvement of Hyper-V, this vulnerability could impact virtualized environments where Windows Server 2025 is used as a hypervisor host, potentially exposing sensitive data from virtual machines or the host itself to an adjacent attacker with network access.

For European organizations, this vulnerability poses a moderate risk primarily to confidentiality of sensitive information hosted on Windows Server 2025 Server Core installations running Hyper-V. Organizations using Hyper-V for virtualization in data centers, cloud environments, or critical infrastructure could face data leakage risks if an attacker gains adjacent network access. This could include exposure of credentials, configuration data, or other sensitive information residing in memory. Sectors such as finance, healthcare, government, and critical infrastructure operators in Europe, which often rely on virtualization for operational efficiency and data isolation, could be particularly impacted. The requirement for adjacent network access limits the attack surface to internal networks or those with weak segmentation, emphasizing the importance of network controls. The absence of known exploits in the wild reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once the vulnerability details are public. The medium CVSS score (5.7) reflects a balance between the high confidentiality impact and the limited attack vector and privileges required. The vulnerability does not affect system integrity or availability, so operational disruption is unlikely, but data confidentiality breaches could lead to regulatory compliance issues under GDPR and damage organizational reputation.

1. Network Segmentation: Implement strict network segmentation and isolation for servers running Windows Server 2025 Server Core with Hyper-V to limit adjacent network access only to trusted and necessary systems. 2. Access Controls: Enforce least privilege principles and restrict administrative and user access to Hyper-V hosts to minimize the pool of authorized attackers. 3. Monitoring and Detection: Deploy network monitoring and intrusion detection systems to identify unusual lateral movement or data exfiltration attempts within internal networks. 4. Patch Management: Monitor Microsoft security advisories closely and apply security patches promptly once available for Windows Server 2025 to remediate the vulnerability. 5. Virtualization Security Best Practices: Use secure configuration baselines for Hyper-V hosts, including disabling unnecessary services and features, and ensure virtual machine isolation is properly configured. 6. Incident Response Preparedness: Prepare incident response plans that include scenarios involving internal network threats and information disclosure to enable rapid containment. 7. Data Encryption: Where feasible, encrypt sensitive data in memory or at rest to reduce the impact of potential information disclosure. 8. Network Access Controls: Use network access control lists (ACLs) and firewall rules to restrict communication paths to and from Hyper-V hosts, limiting exposure to adjacent network attackers.