Nuendo 7.1.40 is the last update for Nuendo 7. You can download it here:
https://www.steinberg.net/en/support/downloads/nuendo_7.html
Nuendo 8 was released 9 months ago, and it’s too far ahead in terms of development to make it practical to continue releasing updates for Nuendo 7. In May, they’re planning to release an update that will add the new Cubase 9.5 features to Nuendo 8 for free. In comparison, Nuendo 7 is still based on the Cubase 8 sequencer engine from 2014.