PrintNightmare vulnerability explained: Exploits, patches, and workarounds Public exploits are available for a remote code execution vulnerability in the Windows Print Spooler that could allow attackers to take full control of systems. The vulnerability affects all editions of Windows and organisations are urged to deploy the patches as soon as possible. Credit: Dreamstime Microsoft has started releasing emergency security updates to fix a publicly disclosed remote code execution vulnerability in the Windows printing functionality that could allow attackers to take full control of vulnerable systems. The vulnerability, dubbed PrintNightmare and tracked as CVE-2021-34527, is located in the Windows Print Spooler service and the public exploits available for it are being improved. Organisations are urged to deploy the patches as soon as possible or disable inbound remote printing until the patches can be applied.