What is CVE-2026-15664?

CVE-2026-15664 is a high-severity vulnerability in Mdmag Quill Forms | Conversational Multi Step Forms, Surveys & Quizzes, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-09-19.

How severe is CVE-2026-15664?

High severity. CVSS v3 base score is 7.2 out of 10.

XSS in Mdmag Quill Forms | Conversational Multi Step Forms, Surveys & Quizzes

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 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.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Mdmag Quill Forms | Conversational Multi Step Forms, Surveys & Quizzes

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-15664?: CVE-2026-15664 is a high-severity vulnerability in Mdmag Quill Forms | Conversational Multi Step Forms, Surveys & Quizzes, classified under Cross-site Scripting. CVSS score: 7.2/10. Published 2026-09-19.
How severe is CVE-2026-15664?: High severity. CVSS v3 base score is 7.2 out of 10.