Windows 7 reached its End of Life on January 14, therefore there will be no other bug fixes or free security updates from now on. Microsoft says that a bugfix will be provided for organizations that purchased Windows 7 Extended Security Updates (ESU) to fix a newly acknowledged issue leading to the desktop wallpaper being replaced by a blank black screen. The wallpaper issue was acknowledged by Microsoft today following numerous reports coming from users after the last update, the KB4534310 Monthly Rollup, was released on the same day.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-to-fix-windows-7-black-wallpaper-bug-for-esu-customers/