The Zero-day exploit grants attackers full Remote Code Execution capabilities on fully patched Windows Print Spooler devices.
Now Microsoft has released a patch for the issue as KB5004945 (still to be populated).
The update is being released for all supported versions of Windows 10, taking versions 2004, 20H2, and 21H1, to builds 19041.1083, 19042.1083, and 19043.1083, respectively
The updates are mandatory and are being pushed out to the operating systems, and can also be downloaded via the Update Catalog here.
Other older versions of Windows may get their own version of the patch later.