# Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder <= 6.2.16 - Authenticated (Fluent Forms Manager+) Server-Side Request Forgery via Mailchimp API Key

- **ID:** WPSEC-2026-2295
- **Plugin:** Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder (`fluentform`), https://wordpress.org/plugins/fluentform/
- **Affected versions:** all versions before 6.2.17
- **Fixed in:** 6.2.17 (Update to 6.2.17 or later.)
- **Severity:** Medium 5.5 (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N)
- **Weakness:** CWE-918
- **Usage among sites WPSec scans:** plugin High, affected versions High (as of 2026-11-03)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/fluentform
- **Fix released:** 2026-11-02
- **Published:** 2026-11-03
- **URL:** https://wpsec.com/vuln/WPSEC-2026-2295/

## Description

The Fluent Forms plugin for WordPress is vulnerable to Server-Side Request Forgery via the Mailchimp API key in the global settings in all versions up to, and including, 6.2.16, due to the data-center part of the API key being placed into the API request host without validation. This makes it possible for authenticated attackers who are Fluent Forms managers with settings-manager permission to make HTTPS GET requests to arbitrary hosts from the web application, which can be used to reach internal services.

## References

- https://wpsec.com/vuln/WPSEC-2026-2295/
- https://plugins.svn.wordpress.org/fluentform/tags/6.2.17/
- https://wordpress.org/plugins/fluentform/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-2295/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.