CVE-2026-86833 PUBLISHED

MetForm < 4.3.1 - Unauthenticated HTML Injection in Notification Emails via Field Shortcodes

Assigner: WPScan
Reserved: 08.09.2026 Published: 07.10.2026 Updated: 07.10.2026

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.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CVSS Score: 5.4

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	Low
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Unknown
Product	MetForm
Versions	Default: unaffected affected from 0 to 4.3.1 (excl.)

Credits

vuxvinh finder
WPScan coordinator

References

https://wpscan.com/vulnerability/6d6850d6-6fdf-4b97-9ccb-c90f9ed01ab0/

Problem Types

CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') CWE