CVE-2025-59502 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting Microsoft Windows 10 Version 1809, specifically build 10.0.17763.0. The flaw resides in the Windows Remote Procedure Call (RPC) service, which handles inter-process communication and remote management functions. An unauthenticated attacker can exploit this vulnerability remotely over the network without requiring user interaction or privileges. By sending specially crafted RPC requests, the attacker can cause the targeted system to consume excessive resources such as CPU, memory, or network bandwidth, leading to denial-of-service conditions. This can result in system slowdowns, service outages, or crashes, impacting availability but not confidentiality or integrity. The CVSS v3.1 base score is 7.5, reflecting high severity due to network attack vector, low attack complexity, no privileges required, and no user interaction needed. The vulnerability was reserved in mid-September 2025 and published in October 2025, with no known exploits in the wild or patches currently available. The lack of patches necessitates alternative mitigations such as network-level controls and monitoring. Given the critical role of RPC in Windows environments, exploitation could disrupt enterprise operations, especially in environments where Windows 10 Version 1809 remains in use despite newer versions being available.

The primary impact of CVE-2025-59502 is denial of service, which can significantly disrupt business operations by making affected systems unresponsive or unavailable. For European organizations, this can affect critical services relying on Windows 10 Version 1809, including enterprise servers, workstations, and network management systems. Industries such as finance, healthcare, manufacturing, and government services could experience operational downtime, leading to financial losses, regulatory non-compliance, and reputational damage. The vulnerability does not compromise data confidentiality or integrity but undermines system availability, which is crucial for continuous service delivery. The ease of exploitation and lack of required privileges increase the risk of widespread attacks, especially in environments with exposed RPC endpoints. Organizations that have not upgraded from Windows 10 Version 1809 or have legacy systems are particularly vulnerable. The absence of known exploits currently provides a window for proactive defense, but the potential for future exploitation remains high.

1. Immediately restrict inbound network access to RPC services (typically TCP ports 135 and dynamic RPC ports) using firewalls and network segmentation to limit exposure to untrusted networks. 2. Apply any official patches or security updates from Microsoft as soon as they become available; monitor Microsoft security advisories closely. 3. For environments where patching is not immediately possible, implement intrusion detection and prevention systems (IDS/IPS) to detect anomalous RPC traffic patterns indicative of exploitation attempts. 4. Disable or limit RPC services on systems where they are not required to reduce the attack surface. 5. Employ network-level rate limiting and traffic shaping to mitigate resource exhaustion attempts. 6. Conduct regular vulnerability assessments and penetration testing focusing on RPC services to identify and remediate exposure. 7. Maintain up-to-date asset inventories to identify systems running the affected Windows 10 Version 1809 build and prioritize their remediation or upgrade. 8. Educate IT staff on monitoring RPC-related logs and alerts to detect early signs of exploitation.