Vulnerability Description
The Divi Form Builder plugin for WordPress is vulnerable to Arbitrary File Upload leading to Remote Code Execution in all versions up to and including 5.1.8. This is due to insufficient file extension validation in the do_image_upload() function where user-supplied input from the acceptFileTypes POST parameter is directly interpolated into a regular expression used to validate uploaded files. Attackers can specify PHP-executable extensions such as .phtml, .phar, .php5, or .php7 to bypass the plugin's .htaccess protection which only blocks .php files specifically. Additionally, on Nginx-based servers, the .htaccess protection is completely ineffective as Nginx does not process .htaccess files. This makes it possible for unauthenticated attackers (who can obtain a nonce from any public page containing a form) to upload executable PHP files to the publicly accessible /wp-content/uploads/de_fb_uploads/ directory and achieve Remote Code Execution by accessing the uploaded file via HTTP. The vulnerability was partially patched in version 5.1.3.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://diviengine.com/divi-form-builder-changelog/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/9692deb2-2526-4983-8a1
FAQ
What is CVE-2026-5524?
CVE-2026-5524 is a vulnerability with a CVSS score of 9.8 (CRITICAL). The Divi Form Builder plugin for WordPress is vulnerable to Arbitrary File Upload leading to Remote Code Execution in all versions up to and including 5.1.8. This is due to insufficient file extension...
How severe is CVE-2026-5524?
CVE-2026-5524 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-5524?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.