CVE-2026-24991: CF7 Extensions Auth Bypass Vulnerability

CVE-2026-24991 Overview

CVE-2026-24991 is an Authorization Bypass Through User-Controlled Key vulnerability (CWE-639) affecting the Extensions For CF7 WordPress plugin developed by HT Plugins. This Insecure Direct Object Reference (IDOR) vulnerability allows attackers to exploit incorrectly configured access control security levels, potentially gaining unauthorized access to sensitive data by manipulating user-controlled key parameters.

Critical Impact

Unauthenticated attackers can bypass authorization controls and access restricted resources by manipulating object references, potentially exposing sensitive form submission data.

Affected Products

• HT Plugins Extensions For CF7 version 3.4.0 and earlier
• WordPress installations using the extensions-for-cf7 plugin
• Contact Form 7 implementations extended with this plugin

Discovery Timeline

• 2026-02-03 - CVE-2026-24991 published to NVD
• 2026-02-03 - Last updated in NVD database

Technical Details for CVE-2026-24991

Vulnerability Analysis

This vulnerability stems from CWE-639: Authorization Bypass Through User-Controlled Key, commonly known as Insecure Direct Object Reference (IDOR). The Extensions For CF7 plugin fails to properly validate user authorization when accessing resources identified by user-supplied parameters. This allows attackers to manipulate object references (such as form entry IDs or user identifiers) to access data belonging to other users without proper authentication or authorization checks.

The vulnerability can be exploited over the network without requiring authentication or user interaction. While the impact is limited to unauthorized information disclosure (confidentiality breach), it poses a significant risk to WordPress sites handling sensitive form submissions through Contact Form 7.

Root Cause

The root cause of this vulnerability lies in improper access control implementation within the Extensions For CF7 plugin. The plugin accepts user-controlled key parameters (such as entry IDs or form identifiers) without adequately verifying that the requesting user has authorization to access the associated resources. This creates a condition where any user can potentially access any form entry by simply modifying the reference parameter in their request.

Attack Vector

The attack vector for CVE-2026-24991 is network-based, requiring no authentication or privileges. An attacker can exploit this vulnerability by:

1. Identifying endpoints in the Extensions For CF7 plugin that accept object reference parameters
2. Manipulating these parameters (such as incrementing or decrementing numeric IDs)
3. Accessing form entries or data belonging to other users without proper authorization
4. Enumerating through multiple entries to harvest sensitive information submitted via Contact Form 7

The vulnerability requires no user interaction, making it particularly dangerous for automated exploitation attempts. For detailed technical analysis, refer to the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2026-24991

Indicators of Compromise

• Unusual access patterns to form entry endpoints with sequential or enumerated ID parameters
• High volume of requests from single IP addresses targeting Extensions For CF7 plugin endpoints
• Access log entries showing attempts to access form entries with IDs outside normal user scope
• Unexpected data exports or access to Contact Form 7 submission data

Detection Strategies

• Monitor WordPress access logs for suspicious parameter manipulation in requests to the Extensions For CF7 plugin
• Implement Web Application Firewall (WAF) rules to detect IDOR attack patterns
• Enable detailed logging for Contact Form 7 and Extensions For CF7 plugin activities
• Deploy intrusion detection systems to identify enumeration attempts against plugin endpoints

Monitoring Recommendations

• Configure alerting for anomalous access patterns to form entry endpoints
• Implement rate limiting on plugin API endpoints to slow down enumeration attacks
• Review access logs regularly for signs of unauthorized data access attempts
• Set up real-time monitoring for failed authorization attempts in WordPress audit logs

How to Mitigate CVE-2026-24991

Immediate Actions Required

• Update Extensions For CF7 plugin to a patched version when available from HT Plugins
• Audit recent access logs for any signs of exploitation
• Review and restrict access to sensitive form submission data
• Consider temporarily disabling the plugin if handling highly sensitive data until a patch is available

Patch Information

WordPress administrators should monitor the HT Plugins website and WordPress plugin repository for security updates addressing this vulnerability. The issue affects Extensions For CF7 versions from n/a through 3.4.0. Upgrade to a version higher than 3.4.0 when a patched release becomes available. For additional details and patch status, consult the Patchstack WordPress Vulnerability Report.

Workarounds

• Implement additional access control checks at the web server or WAF level
• Restrict access to the WordPress admin area and plugin endpoints using IP allowlisting
• Disable public access to form entry data exports until a patch is applied
• Consider using a security plugin to add additional authorization layers

# Example: Restrict access to Extensions For CF7 endpoints via .htaccess
<IfModule mod_rewrite.c>
    RewriteEngine On
    # Block direct access to plugin AJAX endpoints from non-admin users
    RewriteCond %{REQUEST_URI} extensions-for-cf7 [NC]
    RewriteCond %{HTTP_COOKIE} !wordpress_logged_in [NC]
    RewriteRule .* - [F,L]
</IfModule>