No, even type-punning properly allocated memory (e.g. using memory to reinterpret the bits of a floating point number as an integer) through pointers is UB because compilers want to use types for alias analysis[1]. In order to do that "properly" you are supposed to use a union. In C++ you are supposed to use the reinterpret_cast operator.
[1] Which IMO goes back to C's original confusion of mixing up machine-level concepts with language-level concepts from the get-go, leaving optimizers no choice but unsound reasoning and blaming programmers when they get it wrong. Something something numerical loops and supercomputers.
I believe using reinterpret_cast to reinterpret a float as an int is undefined behavior, because I don't believe that follows the type aliasing rules [1]. However, you could reinterpret a pointer to a float as a pointer to char, unsigned char, or std::byte and examine it that way.
As far as I'm aware, it's safe to use std::memcpy for this, and I believe compilers recognize the idiom (and will not actually emit code to perform a useless copy).
That's like saying all bugs are undefined behavior. C lets you write to your own stack, so if you corrupt the stack due to an application error (e.g. bounds check), then that's just a bug because you were executing fully-defined behavior. Examples of undefined behavior would be things like dividing by 0 where the result of that operation can differ across platforms because the specific behavior wasn't defined in the language spec.
There are some complicated UBs that arise when casting to different types that are not obviously logic errors (can't remember the specifics but remember dealing with this in the past).
