Time‑of‑check time‑of‑use race condition in the Windows Projected File System allows an authorized local user to manipulate the contents of projected files while the system believes those files are unchanged, potentially compromising data integrity or causing unintended application behavior. The flaw does not enable remote execution or broader network attacks; it requires local authorization.

Microsoft Windows 10 (1809, 21H2, 22H2), Microsoft Windows 11 (23H2, 24H2, 25H2, 26H1, 26H2), and Microsoft Windows Server 2019, 2022, and 2025 (including Server Core), in all supported architectures, are impacted by this defect.

The vulnerability carries a CVSS score of 4.7, indicating moderate severity. EPSS information is not available, and the vulnerability is not listed in the CISA KEV catalog, suggesting it is not a known exploited weakness. The attack vector is exclusively local, requiring an authorized user with appropriate privileges to exploit the race condition and tamper with projected files. While the risk to critical infrastructure may be limited, in environments where projected files are used for essential data, local tampering could lead to data loss or service disruption.