CVE-2026-18100
Received Received - Intake

Stored XSS in MetForm WordPress Plugin

Publication date: 2026-08-25

Last updated on: 2026-08-25

Assigner: Wordfence

Description
The MetForm – Contact Form, Survey, Quiz, & Custom Form Builder for Elementor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'mf_form_id' Widget Setting in all versions up to, and including, 4.1.8 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload bypasses Elementor's save-time wp_kses_post filter because it contains no HTML tags, and MetForm's own str_replace transformation of script tags into JavaScript template literal expressions provides an additional delivery path.

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Meta Information

Published
2026-08-25
Last Modified
2026-08-25
Generated
2026-08-25
AI Q&A
2026-08-25
EPSS Evaluated
N/A
NVD
CVE-2026-18100
EUVD
EUVD-2026-65315

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
wpmet metform to 4.1.8 (inc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

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Executive Summary

This vulnerability is a Stored Cross-Site Scripting (XSS) flaw in the MetForm WordPress plugin. It allows authenticated attackers with contributor-level access or higher to inject malicious scripts into web pages via the 'mf_form_id' widget setting. The issue arises due to insufficient input sanitization and output escaping, enabling script execution when users access the compromised pages.

Detection Guidance

To detect this vulnerability, inspect WordPress sites using MetForm plugin versions up to 4.1.8 for stored XSS via the 'mf_form_id' widget setting. Check for unauthorized script injections in form pages or Elementor content. Use WordPress admin access to review plugin versions and scan for suspicious payloads in form configurations.

Impact Analysis

If exploited, this vulnerability could allow attackers to steal user sessions, deface websites, or redirect visitors to malicious sites. Users with contributor-level access or above on a WordPress site using the vulnerable MetForm plugin could inject scripts that execute when other users view affected pages.

Compliance Impact

This vulnerability could lead to data breaches, compromising user data and violating privacy regulations like GDPR or HIPAA. If exploited, attackers may gain access to sensitive user information, resulting in non-compliance with data protection standards and potential legal consequences.

Mitigation Strategies

Update the MetForm plugin to the latest version beyond 4.1.8 immediately to patch the vulnerability. Remove any unauthorized scripts injected via the mf_form_id widget setting by reviewing and cleaning up affected pages.

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