Executive brief
Quiz and Survey Master is a popular WordPress plugin for creating surveys and quizzes. A user with contributor-level access can inject malicious JavaScript into quiz questions that executes when any visitor views the quiz, potentially stealing credentials, session tokens, or other sensitive information from site visitors.
Technical details
The vulnerability is a stored cross-site scripting (XSS) flaw in the plugin's question creation functionality. The vulnerable component fails to properly escape the "required" setting of polar-type questions before outputting it into an unquoted HTML attribute. An authenticated attacker with contributor-level access or above can inject arbitrary JavaScript via the REST API endpoint /wp-json/quiz-survey-master/v1/questions/. The payload breaks out of the unquoted data-is_required attribute and executes in the browser of any user viewing the quiz. The attack requires contributor-level access and a quiz embedded on a public page via the [mlw_quizmaster] shortcode. The vulnerability was fixed in version 11.2.2.
Affected products
- NextWP Quiz and Survey Master before 11.2.2
Timeline
- 2026-07-27: disclosed
- 2026-08-04: patched: Fixed in version 11.2.2