Vulnerability · Published Jul 2, 2026 · Assigned by Wordfence
CVE-2026-5524Divi Form Builder <= 5.1.8 - Unauthenticated Arbitrary File Upload Leading to Remote Code Execution via 'acceptFileTypes' Parameter
Critical 9.8
In plain English
A critical-severity unrestricted file upload in Divi Form Builder from Divi Engine. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 3.5% (higher than 89% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code.
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Divi Engine | Divi Form Builder | 0 – through 5.1.8 |
Weakness: CWE-434 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H