Microsoft released a patch for a zero-day vulnerability affecting the Windows print spooler. But security researchers released a proof-of-concept for a similar vulnerability thinking it was already patched. It turns out they revealed a completely different zero day vulnerability (CVE-2021-34527), dubbed PrintNightmare. The good news is that it still requires an authenticated user calling RpcAddPrinterDriverEx() because a patch is still in the works. Users and admins should check membership and nested group membership in the groups listed below.”]