CVE-2026-15664
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.53%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- EPSS
- 0.53% probability · 44th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- security@wordfence.com
EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
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
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3663009%40quillforms&new=3663009%40quillforms
- https://www.wordfence.com/threat-intel/vulnerabilities/id/1261881f-7a04-47fb-8176-6a9ac2088f8d?source=cve
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.