CVE-2026-86833
MediumCVSS 5.4Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
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.
Risk Assessment
An attacker can inject malicious HTML into emails, which may lead to phishing, data theft, or infection of recipients' browsers.
Recommendation
Update the MetForm plugin to version 4.3.1 or later, which includes a fix to prevent HTML injection.
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-2026-86834Low
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.
- CVE-2026-18100Medium
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.
Original NVD description (English source)
The MetForm WordPress plugin before 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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS