>This document imposes no requirements on the behavior of programs that contain undefined behavior

That's saying that programs that exhibit undefined behaviour are not governed by the C++ spec. For a program to be a valid, spec governed piece of C++ code it has to exhibit no undefined behaviour (outside of some constraints). Its accurate to say that any undefined behaviour results in the code being executed no longer being C++, and it can have any behaviour. That's synonymous in common developer speak with 'incorrect', as its desirable for your C++ code to be executed as C++