CVE-2026-5524: Divi Form Builder <= 5.1.8 - Unauthenticated Arbitrary File Upload Leading to Remote Code Execution via 'acceptFileTypes' Parameter

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 2 Jul 2026. It cites 1 public report, the first from 2 Jul 2026.

• patchstack.com

How likely is exploitation in the next 30 days?

3.5%

EPSS score, percentile 89.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?

9.8 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• 5.1.8 and earlier

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 30 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

Divi Form Builder <= 5.1.8 - Unauthenticated Arbitrary File Upload Leading to Remote Code Execution via 'acceptFileTypes' Parameter

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.

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 30 Oct 2026. About the data.

Timeline