CVE-2026-18100
MediumCVSS 6.4Exploitation Probability (EPSS)
Low risk12th percentile - higher than 12% of all known CVEs
Summary
The MetForm 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.
Risk Assessment
XSS attacks can lead to user account compromise, data theft, or page content modification, potentially harming the organization's reputation.
Recommendation
Update the MetForm plugin to a version newer than 4.1.8 and audit pages for unauthorized scripts.
Other vulnerabilities in MetForm
See all- CVE-2026-103339Medium
Metform plugin has a stored XSS vulnerability due to improper input neutralization during web page generation. Affects versions up to 4.3.0.
- CVE-2026-114180Medium
The WordPress Metform plugin (through version 4.3.2) contains a Missing Authorization vulnerability due to incorrectly configured access control security levels. This allows exploitation of the flawed authorization settings.
- CVE-2026-86833Medium
The MetForm WordPress plugin before version 4.3.1 does not sanitize or escape submitted form-field values before inserting them into the HTML body of its email notifications, allowing unauthenticated attackers to inject arbitrary markup into the administrator and submitter notification emails the site sends.
- CVE-2026-86834Low
The MetForm WordPress plugin before 4.3.1 does not properly restrict access to a debug file it writes to the web root on every form submission when its HubSpot Forms integration is enabled. This allows unauthenticated attackers to read upstream API response data, including correlation identifiers and cookies.
- CVE-2026-86832Medium
The MetForm WordPress plugin before 4.3.1 does not properly restrict access to form submission data, allowing unauthenticated attackers to view submitter information through the REST API.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS