VulnCrest
Search
Create account
Report an incident
Radar sectionsDatabase
Check my site
WordPress plugin

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

CVE-2026-5524Published · Updated

Action summary

Affected: ≤5.1.8Update to 5.1.9 or newer

All remediation steps
Watch plugin
Severity
Critical9.8
CVSS
9.8
CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
What does this vector mean?
AV:N Attack vector
Network
AC:L Attack complexity
Low
PR:N Privileges required
None
UI:N User interaction
None
S:U Scope
Unchanged
C:H Confidentiality
High
I:H Integrity
High
A:H Availability
High
Weakness
CWE-434 Arbitrary File Upload
Required access
No account needed
Exploit prediction (EPSS)
No score
CISA KEV
Not listed
On this page8

Am I affected?

Divi Form Builder divi-form-builder

  1. Affected≤ 5.1.8
  2. Patched in5.1.9

Update to 5.1.9 or newer.

You are affected if you run ≤ 5.1.8. Version 5.1.9 and later are not affected by this issue.

  • Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Divi Form Builder.
  • No admin access? Run a passive check of your site. It reads public files only.
  • No account is needed to exploit this. Treat any exposed site on an affected version as at risk.

What to do

  1. Update to version 5.1.9, or a newer patched version
  2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
  3. Watch Divi Form Builder to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to 0xd4rk5id3.

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.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

More in Divi Form Builder

All 3
More vulnerabilities in Divi Form Builder
SeverityVulnerabilityCVEPublished
High8.8Authenticated (Subscriber+) Missing Authorization to Privilege Escalation via User Profile Update Form
≤5.1.8Update to 5.1.9
CVE-2026-5523
Critical9.8Unauthenticated Privilege Escalation via 'role'
≤5.1.2Update to 5.1.3
CVE-2026-5118

Same weakness (Arbitrary File Upload)

All Arbitrary File Upload
Other Arbitrary File Upload vulnerabilities
SeverityVulnerabilityCVEPublished
High7.2Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header
EZ SQL Reports Shortcode Widget and DB Backup≤5.25.25Update to 5.26.45
CVE-2026-120688
Critical9.8Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission
Chatterbug Forms – Fast, Flexible WordPress Form Builder≤1.0.2Update to 1.1
CVE-2026-125055
Critical9.8Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter
ELEX WordPress HelpDesk & Customer Ticketing System≤3.3.9Update to 3.4.0
CVE-2026-119077
Medium5.3Unauthenticated Sensitive Information Exposure in 'search' Parameter
Customer Reviews for WooCommerce≤5.127.0Update to 5.128.0
CVE-2026-121518

Timeline

  1. CVE published

    Severity critical, CVSS 9.8

  2. Record last updated

Sources & licenses

Wordfence record
Vulnerability data
Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
CVE® identifiers
Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
CVSS / CWE
National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
VulnCrest content
Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.

How we use these sources

Search VulnCrest Radar

Jump to

Are you sure?