Would you happen to have any examples outside of this particular update where an OS security update goes and changes something that the OS didn't itself create?

Would you happen to have any examples outside of this particular update where an OS security update goes and changes something that the OS didn't itself create? Genuinely curious if this is a thing. The word "system" can be scoped any which way (see system of systems) but typically means "part of the OS" in this context.