Expresstech Quiz and Survey Master Plugin up to 11.2.6 on WordPress Audit Trail qsm_hidden_questions cross site scripting

Summaryinfo

A vulnerability was found in Expresstech Quiz and Survey Master Plugin up to 11.2.6. It has been rated as problematic. Affected is an unknown function of the component Audit Trail. The manipulation of the argument qsm_hidden_questions leads to cross site scripting. This vulnerability is traded as CVE-2026-96558. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Expresstech Quiz and Survey Master Plugin up to 11.2.6 and classified as problematic. This issue affects an unknown function of the component Audit Trail. The manipulation of the argument qsm_hidden_questions with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. The summary by CVE is:

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.

The advisory is shared at wordfence.com. The identification of this vulnerability is CVE-2026-96558 since 09/23/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• Expresstech

Name

• Quiz and Survey Master Plugin

Version

• 11.2.0
• 11.2.1
• 11.2.2
• 11.2.3
• 11.2.4
• 11.2.5
• 11.2.6

CPE 2.3info

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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