CVE-2026-15664High· 7.2▾ Twilight

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…

▾ Twilight zone — High severity, or a signal on a lesser flaw

Depth score40/ 100 · Moderate

impact 39.6 · likelihood 0.1 · exploitation 0

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Proof of concept

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Published

Sep 19, 2026

Updated

Sep 21, 2026

CVSS

7.2

Vendor

mdmag

Product

Quill Forms | Conversational Multi Step Forms, Surveys & quizzes

CWE

CWE-79

Depth score

40 · Moderate

EPSS

0.39% · p32

Platforms

—

Source

NVD

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CISA SSVC

decided 2026-09-19

Exploitation: none
Automatable: yes
Technical impact: partial

Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.

EPSS history

Exploit-prediction probability, daily snapshots since Sep 19.

0.4% → 0.4%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 2 days

Sep 19, 2026Published
Disclosed via NVD
Sep 19, 2026EPSS first tracked
0.4%
Sep 21, 2026Record revised
Last analysed / modified upstream

mdmag CWE-79 #nvd #cve.org

Affected

quill_forms_conversational_multi_step_forms_surveys_quizzes <= 5.7.1

Full technical detail▾

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.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd#cve.org