The latest patch from steam is 1.0.9.5273: https://store.steampowered.com/news/app/1220140/view/3680046320081023916?l=english

But the latest update posted in the forum is 0.9.0.1675: https://www.gog.com/forum/cartel_tycoon/patches_and_updates

It's an old thread, but in case someone else is wondering...
I can see on GOG Database that game seems updated to 1.0.9.6411 since 2023-12-21

However, we seem to be missing "Diva’s Hotel Content pack DLC" (see the Second Class Citizens thread).
I just send a message to the publisher, in case they could do something ! No we just have to hope & wait.