If you have a Windows-based PC running Windows 10 that just received a security update in May 2019, chances are your computer may have a major security flaw, leaving it open to hacking.

A security researcher who calls herself ‘SandboxEscaper’ on GitHub has published the flawed code on GitHub that shows how a hacker can enter the computer at the root level and gain administrator privileges to wreak havoc from within.

This flaw also known as a “zero-day vulnerability” first reported by ZDNet, is what security researchers call a “local privilege escalation (LPE)”. It is called a zero-day vulnerability because it is a flaw known to the software vendor that still doesn’t have a patch in place to fix the flaw. This can be exploited by cybercriminals.