As security researchers address the PrintNightmare the focus on this Windows subsystem has led to discovery of another vulnerability — that is less dangerous as local access to network is needed — but it still needs to be watched/addressed until full patch emerges.
A new, unpatched, vulnerability has been discovered in the Windows Print Spooler and is being tracked under CVE-2021-34481. Discovered by Jacob Baines at Dragos, this one requires local access, so it is less of a nightmare than PrintNightmare, but unfortunately the result of exploitation is SYSTEM level privileges. Unfortunately, the workaround is the same; Stop and disable the Print Spooler service, which, of course, will disable the ability to print, both locally, and remotely. It appears that Jacob will not be providing more details until Def Con.