CVE-2026-62772

This is a security weakness in a Windows driver used for container isolation. If someone already has basic access to the computer, they may be able to overwhelm the driver’s handling of data and turn that into full control of the machine. Think of it like a safety guard on a door that can be broken if someone inside the building pushes too hard—after that, they can get past normal protections.

This matters to you if you run Windows 11 on devices where Windows Container Isolation is used (the unionfs.sys file system filter driver is reachable in that setup). It’s primarily a risk for someone who already has local access (low-privilege), and it does not require special user clicks. The risk is gated by local access and by whether this container isolation driver is reachable on your configuration.

This is RED because the bug enables local privilege escalation to full host control, which can quickly turn an ordinary account into system-level access. Even though there are no reported active attacks in dated reporting and no public exploit code on record, you should treat this as a serious patching priority for any Windows 11 machines using container isolation. Patch Tuesday included this fix, so you should move it to the top of your update queue.