Does granting access to external services expose the privately available repos

I have a GitHub account. I have a few public repos, and I am also part of an organization which has private ones.

Suppose I subscribe (or was already subscribed) to a service like gitbooks.io, or landscape.io, or any other available with GitHub integration and grant access to my repositories. Will they be able to access and see the private repos of the organization I am part of?

Note that I am talking security here, not service access.