CVE-2026-1541: Avada Builder Information Disclosure Flaw

CVE-2026-1541 Overview

The Avada (Fusion) Builder plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 3.15.1. This vulnerability stems from the plugin's fusion_get_post_custom_field() function failing to validate whether metadata keys are protected (underscore-prefixed). This security flaw allows authenticated attackers with Subscriber-level access and above to extract protected post metadata fields that should not be publicly accessible via the Dynamic Data feature's post_custom_field parameter.

Critical Impact

Authenticated attackers can bypass metadata protection mechanisms to access sensitive post custom fields, potentially exposing confidential information stored in protected WordPress metadata.

Affected Products

• Avada (Fusion) Builder plugin for WordPress versions up to and including 3.15.1
• WordPress installations using the vulnerable Avada Builder plugin
• Sites utilizing Avada theme with integrated Fusion Builder functionality

Discovery Timeline

• 2026-04-15 - CVE-2026-1541 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2026-1541

Vulnerability Analysis

This vulnerability is classified under CWE-639 (Authorization Bypass Through User-Controlled Key), which occurs when a system's authorization functionality does not prevent one user from accessing another user's data by modifying a key value. In this case, the Avada (Fusion) Builder plugin exposes protected metadata through the Dynamic Data feature without proper access control validation.

WordPress metadata keys prefixed with an underscore (e.g., _private_key) are conventionally treated as protected and should not be accessible through standard user-facing features. The vulnerability exists because the fusion_get_post_custom_field() function processes metadata retrieval requests without checking whether the requested key is protected, effectively bypassing WordPress's metadata protection conventions.

The attack requires only Subscriber-level authentication, which is the lowest privilege level that allows users to log into a WordPress site. This low barrier to exploitation significantly increases the risk for sites with open registration or membership functionality.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the fusion_get_post_custom_field() function. The function accepts user-supplied metadata key names through the post_custom_field parameter without verifying whether the key is underscore-prefixed (protected). WordPress core treats underscore-prefixed meta keys as private/internal, but this convention is not enforced programmatically—plugins must implement their own validation. The Avada Builder plugin fails to implement this check, allowing any authenticated user to request arbitrary metadata keys including protected ones.

Attack Vector

The attack is network-based and can be executed remotely by any authenticated user with at least Subscriber privileges. An attacker would craft a request to the Dynamic Data feature specifying a protected metadata key (such as _wp_page_template, _edit_lock, or custom protected fields containing sensitive data). The plugin processes this request without validation and returns the protected metadata value to the attacker.

The exploitation flow involves:

1. Authenticating to the WordPress site with Subscriber-level or higher credentials
2. Identifying the Dynamic Data feature endpoint in the Avada Builder plugin
3. Crafting a request with the post_custom_field parameter set to a protected metadata key
4. Receiving the protected metadata value in the response

Since no verified code examples are available, administrators should consult the Wordfence Vulnerability Report for detailed technical analysis and proof-of-concept information.

Detection Methods for CVE-2026-1541

Indicators of Compromise

• Unusual requests to Avada Builder Dynamic Data endpoints containing protected metadata keys (underscore-prefixed)
• Subscriber or low-privilege accounts making repeated metadata retrieval requests
• Access log entries showing post_custom_field parameters with values starting with underscore characters
• Unexpected metadata access patterns from authenticated users who should not require such data

Detection Strategies

• Implement web application firewall (WAF) rules to flag requests containing underscore-prefixed values in the post_custom_field parameter
• Monitor WordPress audit logs for metadata access events from low-privilege user accounts
• Review access logs for patterns of enumeration attempts targeting post metadata endpoints
• Deploy SentinelOne Singularity to detect anomalous application behavior and potential data exfiltration attempts

Monitoring Recommendations

• Enable comprehensive logging for the Avada Builder plugin API endpoints
• Configure alerts for metadata retrieval requests from Subscriber-level accounts
• Implement rate limiting on Dynamic Data feature endpoints to detect enumeration attempts
• Regularly audit protected metadata fields to identify sensitive data that could be exposed

How to Mitigate CVE-2026-1541

Immediate Actions Required

• Update the Avada (Fusion) Builder plugin to a patched version higher than 3.15.1
• Audit subscriber and low-privilege user accounts for suspicious activity
• Review protected metadata fields to assess potential data exposure
• Consider temporarily restricting Dynamic Data feature access to trusted roles only

Patch Information

A security update addressing this vulnerability is available through the plugin vendor. Organizations should update to the latest version of the Avada (Fusion) Builder plugin that includes the fix for CVE-2026-1541. Additional information about the plugin can be found on the ThemeForest Product Page. For detailed vulnerability information and remediation guidance, refer to the Wordfence Vulnerability Report.

Workarounds

• Implement server-level filtering to block requests containing underscore-prefixed post_custom_field values
• Restrict user registration to prevent attackers from obtaining Subscriber-level credentials
• Use a security plugin to limit API access for low-privilege user roles
• Consider disabling the Dynamic Data feature if not required for site functionality

# WordPress configuration - restrict user registration
# Add to wp-config.php to prevent new user registrations
define('WP_DISABLE_ADMIN_EMAIL_VERIFY_SCREEN', true);

# Review and disable user registration in WordPress Settings > General
# Uncheck "Anyone can register" option