Insecure Direct Object Reference in Fluent Forms by WP Fluent Forms
CVE-2026-4160

5.3MEDIUM

Key Information:

Vendor

WordPress
Status
Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder
Vendor
CVE Published:
16 April 2026

What is CVE-2026-4160?

The Fluent Forms plugin, utilized for creating customizable contact forms and surveys on WordPress sites, is vulnerable to an Insecure Direct Object Reference flaw through the 'submission_id' parameter. This security gap exists in versions up to and including 6.1.21 and stems from a lack of authorization and ownership checks within the Stripe SCA confirmation AJAX endpoint. As a result, unauthenticated attackers can exploit this vulnerability to tamper with the payment statuses of pending submissions, potentially modifying them to 'failed' or other unintended states, posing a significant risk to site operators and their users.

Affected Version(s)

Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder 6.1.21

References

https://www.wordfence.com/threat-intel/vulnerabilities/id...
https://plugins.trac.wordpress.org/changeset/3496638/flue...

CVSS V3.1

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Prickly Cactus
.