CVE-2026-69779

CVE-2026-69779 is a time-of-check time-of-use (TOCTOU) race condition (CWE-367) in the Windows Win32K kernel component, assigned by Microsoft. A local, authorized attacker with low privileges can trigger the flaw by racing the window between a security check and the subsequent use of a resource in Win32K system calls; no user interaction is required, though the race condition makes exploitation technically demanding. A successful exploit elevates the attacker's privileges locally, yielding high impact to confidentiality, integrity, and availability (typically SYSTEM-level access). Any Windows system containing the affected Win32K code is exposed, but exploitation requires the attacker to already be able to execute code locally, such as via a compromised user session or malicious local process. As of now there is no evidence of exploitation in the wild, no known public proof-of-concept, and the flaw is not listed in CISA KEV; EPSS estimates only a 0.2% probability of exploitation within 30 days.

What to do: Apply Microsoft's security update for CVE-2026-69779 as part of your regular patch cycle, checking Microsoft's advisory for the exact affected and fixed builds for each Windows edition in your estate. Because exploitation requires local code execution with low privileges and a difficult-to-win race condition, prioritize patching hosts where untrusted users can run code (VDI, shared workstations, multi-user servers). No workarounds are specified in the available data; monitor Microsoft and CISA channels for updates on exploitation status and confirm your asset inventory covers all supported Windows releases.