When the Program access right is globally set. The user can access all xwiki pages also where access is not allowed.

When the Program access right is globally set.

The user can access all xwiki pages also where access is not allowed.

Reproduce via:

Don't allow a user access on a specific xwiki page.
This will show: You are not allowed to view this page or perform this action.
Allow global: Program rights.

The page the wasn't allowed before can now be accessed.