The Quiz and Survey Master (QSM) WordPress plugin before 11.2.4 does not check authorisation when returning question bank entries through one of its REST API routes, allowing users with a role as low as Contributor to read the questions, hints and correct answer keys of quizzes belonging to other users.
The Quiz and Survey Master (QSM) WordPress plugin before 11.2.4 does not perform a per-object ownership check before saving a quiz's front-end text settings, allowing users with contributor-level access and above to modify the text settings of quizzes created by other users.