CVE-2026-3850

Divi <= 4.27.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Contact Form 'redirect_url' Shortcode Parameter

2026-09-01 17:38
Osvaldo Noe Gonzalez Del Rio (Os)

Strategic Overview

Status
Patched in 4.27.7
Affected Theme
Divi
Affected Version
<= 4.27.5
CVSS
6.4Medium
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-3850
View all Divi vulnerabilities

At a glance

CVE-2026-3850 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Divi WordPress theme, affecting versions <= 4.27.5. It carries a CVSS score of 6.4 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Contributor level or above. The issue is fixed in version 4.27.7; sites on affected versions should update now. Disclosed September 2026, reported by Osvaldo Noe Gonzalez Del Rio (Os).

Vulnerability Overview

The Divi theme for WordPress is vulnerable to Stored Cross-Site Scripting via the `redirect_url` parameter of the `et_pb_contact_form` shortcode in all versions up to, and including, 4.27.6. This is due to the `redirect_url` attribute being sanitized with `esc_attr()` instead of `esc_url()` before being rendered into the `data-redirect_url` HTML data attribute. Additionally, `redirect_url` is absent from the hardcoded `$url_options` array in `class-et-builder-element.php`, so it does not receive `esc_url_raw()` sanitization during shortcode parsing. After a successful form submission, client-side JavaScript reads this data attribute and passes it directly to `window.location.href`, executing arbitrary JavaScript from a `javascript:` URI. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that execute whenever a user submits the contact form.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Divi <= 4.27.5 carries this weakness at esc_attr(), and reaching it takes an account at Contributor level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Divi the fix is 4.27.7: builds <= 4.27.5 are affected, anything from 4.27.7 onward is not.

Remediation

Update to version 4.27.7, or a newer patched version

How does WordSec protect against this?

An attacker needs Contributor access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Divi 4.27.7 closes this, and updating the theme is the step that ends it.

  • Firewall
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-3850https://www.wordfence.com/threat-intel/vulnerabilities/id/768fb279-8d35-4002-91d8-c6a3b0f8f51dhttps://nvd.nist.gov/vuln/detail/CVE-2026-3850

Related records

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