Additionally, the patch also has some security updates, including patches for two zero-day bugs that allow elevation of privilege. There are also updates that offer protection against microarchitecture data sampling (MDS) another speculative execution side-channel vulnerability, but this only affects 32-bit users of Windows 10.
Interestingly, The Register collected some complaints that indicate the Cortana issues aren't gone entirely:
But its fix has nixed SearchUI.exe for some. Those griping claim SearchUI.exe, a part of Cortana, won't launch after installing KB4515384.We suppose Microsoft will need to do more beta testing on users to ensure they get to the bottom of this.
"What a mess – I had the original issue with SearchUI.exe and it sending my CPU to unparalleled heights and showing a big black pane of nothing," wrote Reddit user cyrenaic101 in a complaint thread. "So I uninstalled that turd. And then here comes the 'fix' KB4515384. Search completely broken…"
Similar complaints surfaced in another Reddit discussion of the updates.