CVE-2026-87111 Details
Description
The User Registration PRO – Custom Registration Form, Login Form, and User Profile WordPress Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via HTTP Referer Header in all versions up to, and including, 6.2.9 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. This vulnerability is present only in the premium build of the plugin and is not present in the free WordPress.org distribution. The nonce required to call the vulnerable AJAX endpoint is localized into the page source of every front-end page for anonymous visitors, making it fully obtainable by unauthenticated attackers.
A stored cross-site scripting vulnerability has been identified in the User Registration PRO WordPress plugin, specifically in versions through 6.2.9. This vulnerability arises from inadequate input sanitization and output escaping, allowing unauthenticated attackers to inject arbitrary scripts via the HTTP Referer header. The injected scripts are executed when users access the affected pages. This issue is exclusive to the premium version of the plugin and does not affect the free version available on WordPress.org. Notably, the nonce required for the vulnerable AJAX endpoint is accessible to unauthenticated attackers, as it is embedded in the source of every front-end page.
Users are advised to update the User Registration PRO WordPress plugin to version 6.3.0 or a newer patched version.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 16, 2026CISA-ADP
Assessed Oct 16, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| User Registration PRO | <= 6.2.9 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 16, 2026 | CVE Modified | CISA-ADP |
| Oct 16, 2026 | New CVE Received | [email protected] |