I doubt if there has ever been a more appropriate nickname for a vulnerable service than PrintNightmare. There must be a whole host of people in Redmond having nightmares about the Windows Print Spooler service by now.

PrintNightmare is the name of a set of vulnerabilities that allow a standard user on a Windows network to execute arbitrary code on an affected machine (including domain controllers) as SYSTEM, allowing them to elevate their privileges as far as domain admin. Users trigger the flaw by simply feeding a vulnerable machine a malicious printer driver. The problem was made worse by confusion around whether PrintNightmare was a known, patched problem or an entirely new problem. In the end it turned out to be a bit of both.