CVE-2026-86833: Unknown Metform

Medium severity, CVSS 5.4. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Unknown Metform: before 4.3.1 (fixed in 4.3.1)

Published 2026-10-07. Last modified 2026-10-07.