The PublishPress Revisions: Duplicate Posts, Submit, Approve and Schedule Content Changes WordPress plugin before 4.3.1 does not verify that a user requesting to duplicate or revise a post has access to that specific post, only that they can edit posts of that type, allowing users with contributor-level access and above to duplicate another user's private, draft, pending or scheduled post into one they own and read its full content.
https://wpscan.com/vulnerability/c448c858-c5f1-4430-b032-076726715916/