Can't speak for the whole of it, but we travelled from Dushanbe to Khorog and then onwards to Wakhan valley and later turned left into the mountains and away from Afganistan to do a 5 day trek in the mountains. Few hundred of those kilometers are on the border with Afganistan. This was in 2015.

Situations obviously change and cannot say how it is now, but as far as I can tell it is similar to then. Cross-border attacks and kidnappings were rare and we neither had an armed escort nor did we want one.

On trip I worried a bit about road safety (still, not nearly as much as in Nepal) and more about food poisoning (stay long enough and you'll experience it :P), but not really about other kind of threats.

People were generally kind and helpful. We did have local guides to help us.

Would love to return again some day.