“Microsoft also corrected a critical bug that has caused some Windows 10 PCs to remain dangerously unpatched against actively exploited vulnerabilities for several months this year.”
CVE-2024-43491 rolled back fixes on some Windows 10 systems that installed updates from March through August 2024. Microsoft says the build numbers crossed into a range that triggered a code defect. Those users patched on schedule and got silently reopened to bugs already under attack. The fix is two more updates from the same pipeline that broke it.