https://arstechnica.com/gadgets/2021/07/microsofts-emergency-patch-fails-to-fix-critical-printnightmare-vulnerability/ > An emergency patch Microsoft issued on Tuesday fails to fully fix a critical security vulnerability in all supported versions of Windows that allows attackers to take control of infected systems and run code of their choice, researchers said. > The threat, colloquially known as PrintNightmare, stems from bugs in the Windows print spooler, which provides printing functionality inside local networks. Proof-of-concept exploit code was publicly released and then pulled back, but not before others had copied it. Researchers track the vulnerability as CVE-2021-34527.