Gravity Forms <= 2.9.30 - Reflected Cross-Site Scripting via 'form_ids' Parameter
| CVE | CVE-2026-4406 |
|---|---|
| CVSS | 4.7 (Medium) |
| Publicly Published | April 7, 2026 |
| Last Updated | April 7, 2026 |
| Researcher |
Anthony Cihan (Hann1bl3L3ct3r)
- Obviam
|
Description
The Gravity Forms plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the `form_ids` parameter in the `gform_get_config` AJAX action in all versions up to, and including, 2.9.30. This is due to the `GFCommon::send_json()` method outputting JSON-encoded data wrapped in HTML comment delimiters using `echo` and `wp_die()`, which serves the response with a `Content-Type: text/html` header instead of `application/json`. The `wp_json_encode()` function does not HTML-encode angle brackets within JSON string values, allowing injected HTML/script tags in `form_ids` array values to be parsed and executed by the browser. The required `config_nonce` is generated with `wp_create_nonce('gform_config_ajax')` and is publicly embedded on every page that renders a Gravity Forms form, making it identical for all unauthenticated visitors within the same 12-hour nonce tick. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. This vulnerability cannot be exploited against users who are authenticated on the target system, but could be used to alter the target page.
Learn more about Cross-Site Scripting vulnerabilities and how to prevent them.
References
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- docs.gravityforms.com
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Vulnerability Details for Gravity Forms
| Software Type | Plugin |
|---|---|
| Software Slug | gravityforms |
| Patched? | Yes |
| Remediation | Update to version 2.9.31, or a newer patched version |
| Affected Version |
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| Patched Version |
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Recent vulnerabilities in Gravity Forms
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