MetForm: Submitted values inject markup into notification emails
An unauthenticated form submitter can supply HTML in form-field values. The plugin inserts those values into administrator and submitter notification email bodies without sufficient sanitization or escaping, allowing attacker-chosen markup in mail sent by the site. This creates a phishing and content-spoofing primitive; browser JavaScript execution is not established by the description. The affected field names and mail-rendering function are undisclosed. Affected versions: < 4.3.1. The authoritative export identifies 4.3.1 as fixed for this CVE.
- Component
- MetForm
- Plugin slug
metform- Affected
- < 4.3.1
- Safe version
4.3.1- Published
- Oct 07, 2026
This CVE was published Oct 07, 2026 and is one of 29 known issues for this plugin.
Update, patch or deactivate.
Update to 4.3.1 or a later supported release. Treat form values as untrusted text and HTML-escape them before composing email bodies; if limited markup is required, apply a strict allowlist. Keep user content separate from trusted links and branding.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
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.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N