PrintNightmare is a critical security vulnerability affecting the Microsoft Windows operating system.
[9][10] On July 6, 2021, Microsoft started releasing out-of-band (unscheduled) patches attempting to address the vulnerability.
[15] After the patch is applied, only administrator accounts on Windows print server will be able to install printer drivers.
[16] The organization which discovered the vulnerability, Sangfor, published a proof of concept in a public GitHub repository.
[3][17] Apparently published in error, or as a result of a miscommunication between the researchers and Microsoft, the proof of concept was deleted shortly after.