CVE-2026-4160CWE-639

Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder <= 6.1.21 - Insecure Direct Object Reference in Stripe SCA Confirmation to Unauthenticated Payment Status Modification

Medium · published April 16, 2026

CVSS v3.1
5.3
EPSS
0%
Percentile
22.2
In the wild
Unconfirmed
What it is

The Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder plugin for WordPress is vulnerable to Insecure Direct Object Reference via the 'submission_id' parameter in versions up to, and including, 6.1.21. This is due to missing authorization and ownership validation on a user controlled key in the Stripe SCA confirmation AJAX endpoint. This makes it possible for unauthenticated attackers to modify payment status of targeted pending submissions (for example, setting the status to "failed").

The record
Technical detail
CVSS v3.1
5.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00306 · 22.2th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-04-16T13:27Z
EPSS history
Timeline
  • 16 APR 13:27Z
    Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder <= 6.1.21 - Insecure Direct Object Reference in Stripe SCA Confirmation to Unauthenticated Payment Status Modification
    cvelistv5