CVE-2025-55226 is a race condition vulnerability identified in the Graphics Kernel component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The vulnerability arises from improper synchronization during concurrent execution involving shared resources, classified under CWE-362. This flaw allows an authorized local attacker with low privileges to execute code on the affected system by exploiting the timing window where multiple threads or processes access shared resources without adequate locking or synchronization mechanisms. The race condition can lead to corruption or manipulation of memory or execution flow, enabling privilege escalation or arbitrary code execution. The vulnerability requires local access, user interaction, and has a high impact on confidentiality, integrity, and availability, as indicated by the CVSS vector (AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H). No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability was reserved in August 2025 and published in September 2025, indicating it is a recent discovery affecting an older Windows 10 version that is still in use in some environments.

For European organizations, this vulnerability poses a significant risk primarily to systems still running Windows 10 Version 1809, which may be present in legacy environments or specialized industrial setups. Successful exploitation could allow attackers to execute arbitrary code locally, potentially leading to privilege escalation and full system compromise. This can result in data breaches, disruption of critical services, and lateral movement within networks. Given the high impact on confidentiality, integrity, and availability, sensitive data and critical infrastructure could be at risk. The requirement for local access and user interaction somewhat limits remote exploitation but does not eliminate risk, especially in environments where insider threats or social engineering are concerns. Organizations in sectors such as manufacturing, healthcare, and government, which may rely on legacy Windows 10 systems, could face operational disruptions and compliance issues under GDPR if personal data is compromised.

1. Immediate mitigation should focus on upgrading affected systems to a supported and patched version of Windows 10 or later, as Windows 10 Version 1809 is an older release with limited support. 2. Implement strict access controls and limit local user privileges to reduce the risk of exploitation by low-privileged users. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious local code execution attempts. 4. Educate users about the risks of social engineering and the importance of not executing untrusted code or files. 5. In environments where upgrading is not immediately feasible, consider isolating legacy systems from critical networks and enforcing network segmentation to contain potential breaches. 6. Monitor system logs and security alerts for unusual activity related to graphics subsystem or kernel operations. 7. Stay updated with Microsoft advisories for any forthcoming patches or workarounds specific to this vulnerability.