CVE-2026-5797: Quiz and Survey Master (QSM) <= 11.1.0 - Unauthenticated Shortcode Injection Leading to Arbitrary Quiz Result Disclosure via Quiz Answer Text Input Fields

The Quiz And Survey Master plugin for WordPress is vulnerable to Arbitrary Shortcode Execution in versions up to and including 11.1.0. This is due to insufficient input sanitization and the execution of doshortcode() on user-submitted quiz answer text. User-submitted answers pass through sanitizetextfield() and htmlspecialchars(), which only strip HTML tags but do not encode or remove shortcode brackets [ and ]. When quiz results are displayed, the plugin calls doshortcode() on the entire results page output (including user answers), causing any injected shortcodes to be executed. This makes it possible for unauthenticated attackers to inject arbitrary WordPress shortcodes such as [qsmresult id=X] to access other users' quiz submissions without authorization, as the qsmresult shortcode lacks any authorization checks.