Do rvalue references allow dangling references?

Consider the below.

#include <string>
using std::string;

string middle_name () {
    return "Jaan";
}

int main ()
{
    string&& danger = middle_name();   // ?!
    return 0;
}

This doesn't compute anything, but it compiles without error and demonstrates something that I find confusing: danger is a dangling reference, isn't it?