The MPCX Lightbox WordPress plugin 1.2.2 through 1.2.5 does not have any authorisation or authentication on one of its AJAX actions available to unauthenticated users, nor does it check the status of the requested post, allowing unauthenticated visitors to retrieve the title, content or excerpt of arbitrary posts, including private, draft, pending, trashed and password-protected ones.
CWE-862