What’s Vulnerable › Vulnerabilities
CVE-2026-15664: Quill Forms | Conversational Multi Step Forms, Surveys & quizzes <= 5.7.1 - Unauthenticated Stored Cross-Site Scripting via Multiple Choice 'Other' Value
- Severity: high (CVSS 7.2 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-09-19 · updated 2026-09-21
- Weakness: CWE-79
Description
The Quill Forms | Conversational Multi Step Forms, Surveys & quizzes plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Multiple Choice 'Other' Value in all versions up to, and including, 5.7.1 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. The injected script executes in the context of the WordPress admin results view, making administrators the primary target when reviewing submitted form entries.
Affected products
References
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/abstracts/class-block-type.php#L402
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/blocks/multiple-choice/class-multiple-choice-block.php#L199
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/class-form-submission.php#L111
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/class-form-submission.php#L194
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/class-form-submission.php#L262
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/rest-api/controllers/v1/class-rest-entry-controller.php#L191
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/abstracts/class-block-type.php#L402
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/blocks/multiple-choice/class-multiple-choice-block.php#L199
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/class-form-submission.php#L111
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/class-form-submission.php#L194
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/class-form-submission.php#L262
- https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/rest-api/controllers/v1/class-rest-entry-controller.php#L191
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