# CVE-2026-18100: MetForm stored cross-site scripting in form widget

Source: https://junglewise.ai/threats/cve-2026-18100-metform-stored-cross-site-scripting-in-form-widget  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-25. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-18100 · Severity: medium · CVSS 6.4 · Published 2026-08-25

MetForm is a WordPress plugin for building contact forms, surveys, and quizzes within the Elementor page builder. Authenticated users with contributor-level access can inject malicious JavaScript code into form widget settings that executes when other users view the affected page, potentially enabling account takeover, data theft, or malware delivery.

Vendors: [Elementor](https://junglewise.ai/threats/vendors/elementor).

## Quick answers

**Is CVE-2026-18100 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18100 being exploited in the wild.

**How severe is CVE-2026-18100?** Medium severity, with a CVSS score of 6.4, published 25 August 2026.

**Which products and versions are affected?** Elementor MetForm up to 4.1.8.

**Is there a fix for CVE-2026-18100?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-18100 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-18100?** Check whether you run Elementor MetForm at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a stored cross-site scripting (XSS) flaw in the 'mf_form_id' widget setting affecting MetForm versions up to 4.1.8. The root cause is insufficient input sanitization and output escaping in the plugin's form picker component. The attack requires authentication with contributor-level or higher privileges and occurs at page-load time when an attacker-controlled form ID is processed. The payload bypasses Elementor's wp_kses_post filter (which strips HTML tags) by containing no HTML, and exploits MetForm's str_replace transformation that converts script tags into JavaScript template literals, providing an additional injection vector. Patches are available in versions after 4.1.8.

## Affected products

- Elementor MetForm up to 4.1.8

## Timeline

- 2026-08-25: disclosed

## References

- [https://plugins.trac.wordpress.org/browser/metform/tags/4.1.4/controls/form-picker-utils.php](https://plugins.trac.wordpress.org/browser/metform/tags/4.1.4/controls/form-picker-utils.php)
- [https://plugins.trac.wordpress.org/browser/metform/tags/4.1.4/utils/util.php](https://plugins.trac.wordpress.org/browser/metform/tags/4.1.4/utils/util.php)