---
id: CVE-2026-15664
title: >-
  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
  inpu…
summary: >-
  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
  inpu…
severity: high
cvss: 7.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N'
cwe:
  - CWE-79
vendor: mdmag
product: 'Quill Forms | Conversational Multi Step Forms, Surveys & quizzes'
affected:
  - quill_forms_conversational_multi_step_forms_surveys_quizzes <= 5.7.1
published: '2026-09-19'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T13:33:33.387'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-15664'
references:
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/abstracts/class-block-type.php#L402
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/blocks/multiple-choice/class-multiple-choice-block.php#L199
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/class-form-submission.php#L111
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/class-form-submission.php#L194
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/class-form-submission.php#L262
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.6.1/includes/rest-api/controllers/v1/class-rest-entry-controller.php#L191
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/abstracts/class-block-type.php#L402
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/blocks/multiple-choice/class-multiple-choice-block.php#L199
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/class-form-submission.php#L111
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/class-form-submission.php#L194
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/class-form-submission.php#L262
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/browser/quillforms/tags/5.7.0/includes/rest-api/controllers/v1/class-rest-entry-controller.php#L191
    label: security@wordfence.com
  - url: >-
      https://plugins.trac.wordpress.org/changeset?reponame=&old=3663009%40quillforms&new=3663009%40quillforms
    label: security@wordfence.com
  - url: >-
      https://www.wordfence.com/threat-intel/vulnerabilities/id/1261881f-7a04-47fb-8176-6a9ac2088f8d?source=cve
    label: security@wordfence.com
tags:
  - nvd
  - cve.org
epss: 0.00386
epssPercentile: 0.32587
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-19T13:24:48.693066Z'
ingestedAt: '2026-09-19T07:59:56.114Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.