On April 17 2026, the CVE Feed announced a new vulnerability—CVE-2026-5797—that exposes quiz answers from other users on WordPress sites using the Quiz and Survey Master (QSM) plugin. The flaw allows unauthenticated attackers to inject arbitrary shortcodes into user-submitted answer text, causing the plugin to execute these shortcodes during result display.
What We Know
The CVE details reveal that versions up to 11.1.0 of QSM are affected. The vulnerability stems from insufficient input sanitization: user answers pass through sanitize_text_field() and htmlspecialchars(), which strip HTML tags but leave shortcode brackets [ ]. When the plugin calls do_shortcode() on the entire results page—including the user’s answers—any injected shortcodes are executed. Attackers can use shortcodes like [qsm_result id=X] to retrieve other users’ quiz submissions without authorization, as the qsm_result shortcode lacks any checks.
Source: News Source
Business Impact
The exposure of quiz answers can lead to:
- Privacy breaches: Sensitive data may be disclosed to unauthorized parties, violating GDPR or HIPAA regulations.
- Revenue loss: Trust erosion may reduce customer engagement and revenue.
- Operational disruption: Inconsistent data retrieval could interfere with analytics and reporting.
For SMBs that rely on quizzes for marketing or lead generation, this vulnerability threatens the integrity of their data collection processes. Enterprise CISOs should assess whether QSM is used in critical systems and evaluate the risk of compromised user information.
What to Do
- Upgrade immediately: Install the latest version of QSM (≥ 11.2.0). If no newer release exists, consider removing or disabling the plugin until a patch arrives.
- Sanitize input: Ensure that all user inputs are fully sanitized—remove shortcode brackets and escape characters—to prevent execution of arbitrary shortcodes.
- Restrict shortcodes: Configure QSM to limit or disable shortcode usage within quiz responses.
- Implement WAF rules: Add firewall rules that block suspicious shortcode patterns in HTTP requests.
- Audit logs: Monitor for unexpected shortcode execution and review audit logs regularly.
If immediate upgrade is not feasible, apply the above mitigations as interim measures to reduce risk until a patch is available.
The Bigger Picture
This incident underscores a recurring issue with WordPress plugins that mishandle user input. Vigilance in plugin security, regular updates, and rigorous sanitization practices are essential for safeguarding data integrity across all web platforms.
How We Can Help
DefendMyBusiness collaborates with 400+ technology providers to help organizations select the right security solutions. If you need a quick assessment of your WordPress environment or guidance on mitigating this vulnerability, visit our contact page: https://defendmybusiness.com/contact. For an initial scan, use our free security tool available on our site.
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