As I understood it, your question is if somebody could patent your invention in a non-US country after you showed it to them.
I'll assume your non provisional is validly filed but not yet published.
There are two risks.
One, improvements. Everyone knowing about your invention can file patent applications for improvements. If there is no NDA or similar provision, that's completly legal. For places like Europe, your patent application will count as prior art for non-obviousness/inventiveness only if the other application is filed after your application publishes.
In theory, if there is no NDA etc., you telling other people could count as a publication, but proving that and the exact content etc. ... So that's one risk.
The other one, somebody else filing the same (your) invention elswhere. Art. 54 EPC (Europe) as an example provides that a patent application may not be granted if the same invention has
been published or
the content of an ep patent application or a PCT designating EP (effectively from the filing date).
So your unpublished US aplication is not prior art for an EP application! If you file a PCT (designating EP) or EP application with valid priority to the US application, you can heal that. (Which is only possible up to 12 months after the first application, so if your application claimed pirority of a provisional, that's 12 months after the filing date of the provisional!)
I can't talk about all countries, so there might be some where even a PCT application is not enough, but it would at least enable you to get the older patent right. In Japan for example, a translation of the PCT application needs to be filed. There seem to be countries where the national phase needs to be entered for the application to be considered as prior art for novelty. So the risk of someone patenting your invention in other countries if you don't have the money to pursue the PCT application there exists.
That means, without an PCT (costs a lot of money),:
if you tell someone about your invention, they could file it somewhere else. That would be illegal, but it would be up to you to prove they stole it. Or at least that you publicly disclosed it, which would count as prior art.
I can't talk about all countries, so there might be some where even a PCT application is not enough, but it would at least enable you to get the older patent right.
To summ it up:
if you have the money and will and can still validly claim priority to the first application (yes, ppas count) to file a PCT and the priority holds because the first filing was well written -> improvement filings, but those can come after the normal publicaion anyways.
If any of those answers no -> there is a risk.