An anonymous reader writes: Google today shared details about a security flaw in Windows, just 10 days after disclosing it to Microsoft on October 21. To make matters worse, Google says it is aware that this critical Windows vulnerability is being actively exploited in the wild. That means attackers have already written code for this specific security hole and are using it to break into Windows systems.In a blog post, security researchers at Google write, "The Windows vulnerability is a local privilege escalation in the Windows kernel that can be used as a security sandbox escape. It can be triggered via the win32k.sys system call NtSetWindowLongPtr() for the index GWLP_ID on a window handle with GWL_STYLE set to WS_CHILD. Chrome's sandbox blocks win32k.sys system calls using the Win32k lockdown mitigation on Windows 10, which prevents exploitation of this sandbox escape vulnerability."