CVE-2026-96558 Cross-site scripting in Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker
Unauthenticated attackers can inject arbitrary scripts via the qsm_hidden_questions parameter, leading to stored XSS when users view affected pages.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-96558?
CVE-2026-96558 is a high-severity cross-site scripting vulnerability in expresstech Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker, published on 10 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The Quiz and Survey Master (QSM) – Quiz Maker & Survey Maker plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via the 'qsm_hidden_questions' parameter in all versions up to, and including, 11.2.6 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the attacker to force the mlw_results INSERT to fail by submitting an over-length or duplicate qsm_unique_key value, which triggers the audit trail code branch that writes the unescaped payload to wp_mlw_qm_audit_trail.form_data.
Weakness: CWE-79
Which versions are affected by CVE-2026-96558?
How do I fix CVE-2026-96558?
No fix has been published for CVE-2026-96558 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-96558 being exploited?
There is no known exploitation of CVE-2026-96558 in the wild and no public exploit code.
Sources
Also known as GHSA-ff7g-f75x-5gp5.