CVE-2026-5797: expresstech quiz and survey master (qsm) – easy quiz and survey maker Injection

Vulnerability summary

CVE-2026-5797 is a medium (CVSS 5.3) Injection vulnerability in expresstech quiz and survey master (qsm) – easy quiz and survey maker. EPSS estimates a 0.67% chance of exploitation in the next 30 days, higher than 51% of scored vulnerabilities.

Timeline

1. 17-04-2026
   PublishedVulnerability first disclosed.
2. 17-04-2026
   Last modifiedVulnerability information updated.

Description

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 do_shortcode() on user-submitted quiz answer text. User-submitted answers pass through sanitize_text_field() and htmlspecialchars(), which only strip HTML tags but do not encode or remove shortcode brackets [ and ]. When quiz results are displayed, the plugin calls do_shortcode() 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 [qsm_result id=X] to access other users' quiz submissions without authorization, as the qsm_result shortcode lacks any authorization checks.

• CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.