CVE-2026-4882
Arbitrary File Upload in User Registration Advanced Fields WordPress Plugin
Publication date: 2026-05-02
Last updated on: 2026-05-05
Assigner: Wordfence
Description
Description
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| wpuserregistration | user_registration_advanced_fields | to 1.6.20 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-434 | The product allows the upload or transfer of dangerous file types that are automatically processed within its environment. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
The User Registration Advanced Fields plugin for WordPress has a vulnerability that allows unauthenticated attackers to upload arbitrary files to the server. This happens because the plugin's 'URAF_AJAX::method_upload' function does not properly validate the type of files being uploaded. This vulnerability exists in all versions up to and including 1.6.20.
The vulnerability can only be exploited if a 'Profile Picture' field is added to the registration form, which is a feature of the plugin.
Because attackers can upload arbitrary files, this could potentially lead to remote code execution on the affected server.
How can this vulnerability impact me? :
This vulnerability can have severe impacts including unauthorized access and control over your WordPress site.
- Attackers can upload malicious files to your server.
- It may lead to remote code execution, allowing attackers to run arbitrary code on your server.
- This can result in data breaches, defacement of your website, or use of your server for malicious activities.
- Since the vulnerability requires no authentication, it can be exploited by anyone.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should immediately remove or disable the "Profile Picture" field from any registration forms using the User Registration Advanced Fields plugin, as the vulnerability can only be exploited if this field is present.
Additionally, update the User Registration Advanced Fields plugin to a version later than 1.6.20 where the vulnerability is fixed.
Ensure that your WordPress installation and all plugins are kept up to date to prevent exploitation of known vulnerabilities.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
The vulnerability allows unauthenticated attackers to upload arbitrary files to the affected WordPress site, potentially leading to remote code execution. This could result in unauthorized access to sensitive data or disruption of services.
Such unauthorized access and potential data breaches could negatively impact compliance with data protection regulations like GDPR and HIPAA, which require safeguarding personal and sensitive information against unauthorized access and ensuring system integrity.
However, the provided context does not explicitly detail the direct impact on compliance with these standards.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability involves arbitrary file uploads through the 'URAF_AJAX::method_upload' function in the User Registration Advanced Fields WordPress plugin when a 'Profile Picture' field is present.
To detect exploitation attempts or presence of this vulnerability on your system, you can monitor HTTP requests for suspicious file upload activity targeting the AJAX upload endpoint related to this plugin.
Suggested commands include searching your web server logs for POST requests containing file uploads to the plugin's AJAX handler, for example:
- grep -i 'URAF_AJAX' /var/log/apache2/access.log
- grep -i 'method_upload' /var/log/apache2/access.log
- grep -i 'profile_picture' /var/log/apache2/access.log
Additionally, you can look for unexpected files uploaded to your WordPress uploads directory or other writable directories by running commands like:
- find /path/to/wordpress/wp-content/uploads/ -type f -mtime -7
Note that the exact AJAX endpoint URL or parameter names may vary depending on your plugin version and configuration, so adjust the search terms accordingly.