Intel x86 Stack Handling Flaw allows kernel access

https://www.bleepingcomputer.com/news/security/multiple-os-vendors-release-security-patches-after-misinterpreting-intel-docs/
In certain circumstances after the use of certain Intel x86-64 architecture instructions, a debug exception pointing to data in a lower ring (for most operating systems, the kernel Ring 0 level) is made available to operating system components running in Ring 3," the CERT/CC team explained in an advisory published yesterday.

Explained in layman's terms, "this may allow an attacker to utilize operating system APIs to gain access to sensitive memory information or control low-level operating system functions."

>>3
It means that unprivileged programs, that are launched without admin rights(thats is what windows does by default regardless of what account is in use) will get kernel access. Thats why all OSes are patched now.