CVE-2026-2626: Divi Booster WordPress Plugin CSRF Vulnerability

CVE-2026-2626 Overview

CVE-2026-2626 is a high-severity vulnerability affecting the Divi Booster WordPress plugin before version 5.0.2. The vulnerability exists due to missing authorization and CSRF (Cross-Site Request Forgery) checks in one of the plugin's fixing functions. This security flaw allows unauthenticated users to modify stored plugin options. More critically, due to the use of unserialize() on user-controlled data, this vulnerability can be chained with a PHP gadget chain to achieve PHP Object Injection, potentially leading to remote code execution.

Critical Impact

Unauthenticated attackers can modify plugin settings and potentially achieve PHP Object Injection through unsafe deserialization, which may lead to remote code execution on affected WordPress installations.

Affected Products

• Divi Booster WordPress plugin versions prior to 5.0.2

Discovery Timeline

• 2026-03-11 - CVE-2026-2626 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2026-2626

Vulnerability Analysis

This vulnerability combines two distinct security weaknesses that create a severe attack chain. The primary issue is the absence of proper authorization checks and CSRF protection in a plugin function responsible for modifying configuration options. Without these security controls, any unauthenticated user can invoke this function and alter the plugin's stored settings.

The secondary and more dangerous aspect involves the use of PHP's unserialize() function on data that can be influenced by attackers. When untrusted data is passed to unserialize(), an attacker can craft malicious serialized objects that, when deserialized, trigger a chain of method calls (known as a gadget chain) present in the application or its dependencies. This technique, known as PHP Object Injection, can lead to arbitrary code execution, file manipulation, or other severe security impacts depending on available gadget chains.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any prior authentication or user interaction, though exploitation complexity is elevated due to the need for a suitable gadget chain.

Root Cause

The root cause is twofold: first, the plugin fails to implement proper capability checks using WordPress functions like current_user_can() and lacks nonce verification for CSRF protection. Second, the plugin uses the unsafe unserialize() function on data that can be controlled by attackers instead of using safer alternatives like json_decode() or maybe_unserialize() with proper validation.

Attack Vector

The attack is network-based (CWE-352: Cross-Site Request Forgery). An attacker can send crafted HTTP requests to the vulnerable endpoint without authentication. The exploitation flow involves:

1. Identifying the vulnerable fixing function endpoint in the Divi Booster plugin
2. Crafting a malicious request to modify plugin options
3. Injecting a serialized PHP object payload designed to exploit available gadget chains
4. Achieving code execution when the malicious serialized data is deserialized

The vulnerability requires no privileges and no user interaction, though the high attack complexity reflects the need for a compatible PHP gadget chain to achieve full code execution. For detailed technical information, refer to the WPScan Vulnerability Report.

Detection Methods for CVE-2026-2626

Indicators of Compromise

• Unexpected changes to Divi Booster plugin options or settings in the WordPress database
• Suspicious POST requests to Divi Booster plugin endpoints from unauthenticated sources
• Serialized PHP object strings appearing in plugin option values, particularly those containing unusual class names
• Web server logs showing requests to plugin AJAX handlers without proper nonce parameters

Detection Strategies

• Monitor WordPress wp_options table for unexpected modifications to Divi Booster-related entries
• Implement Web Application Firewall (WAF) rules to detect serialized PHP objects in request parameters
• Review Apache/Nginx access logs for POST requests targeting the Divi Booster plugin from external IPs
• Deploy file integrity monitoring to detect unauthorized PHP file modifications that may result from successful exploitation

Monitoring Recommendations

• Enable WordPress audit logging to track option changes and plugin configuration modifications
• Configure SIEM alerts for patterns indicative of PHP object injection attempts (e.g., O: prefix in POST data)
• Monitor for new or modified PHP files in the WordPress installation, especially in plugin and upload directories
• Implement real-time alerting for unauthorized administrative actions in WordPress

How to Mitigate CVE-2026-2626

Immediate Actions Required

• Update the Divi Booster plugin to version 5.0.2 or later immediately
• Audit the wp_options table for any suspicious or unexpected Divi Booster configuration changes
• Review server logs for evidence of exploitation attempts prior to patching
• If exploitation is suspected, perform a full malware scan and consider restoring from a known-clean backup

Patch Information

The vulnerability has been addressed in Divi Booster version 5.0.2. Site administrators should update to this version or later through the WordPress plugin update mechanism. For additional details and verification, consult the WPScan Vulnerability Report.

Workarounds

• If immediate patching is not possible, temporarily disable the Divi Booster plugin until the update can be applied
• Implement WAF rules to block requests containing serialized PHP objects to WordPress plugin endpoints
• Restrict access to WordPress administrative endpoints at the web server level using IP allowlisting
• Enable WordPress application-level firewalls such as Wordfence or Sucuri with rules to detect object injection attempts