CVE-2026-4160
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe 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").
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Fluent Forms WordPress plugin versions up to 6.1.21 contain an Insecure Direct Object Reference vulnerability in its Stripe SCA confirmation AJAX endpoint. The 'submission_id' parameter lacks proper authorization and ownership validation, allowing unauthenticated attackers to modify the payment status of any pending submission by manipulating this parameter.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm Fluent Forms plugin is installedCheck the WordPress plugins directory or access wp-admin > Plugins to verify Fluent Forms is activeAffected if Fluent Forms plugin is present and active in the WordPress installation
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Identify installed Fluent Forms versionNavigate to Plugins page in WordPress admin, find Fluent Forms, and note the version number displayed in the plugin description; alternatively check the version in the plugin header file (fluent-form.php)Affected if Version is 6.1.21 or earlier
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Verify Stripe SCA integration is configuredGo to Fluent Forms settings in WordPress admin, check for Stripe payment integration settings, and confirm if Stripe SCA (Stripe Customer Authentication) feature is enabledAffected if Stripe SCA is enabled and configured as a payment method in Fluent Forms settings
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Locate the Stripe SCA AJAX endpointInspect the Fluent Forms plugin files for the AJAX handler processing Stripe SCA confirmation requests, typically found in includes/routes or similar directories handling payment callbacksAffected if The AJAX endpoint handling submission_id parameter is accessible without authentication
Environment is affected if Fluent Forms version is 6.1.21 or earlier AND Stripe SCA payment integration is enabled, allowing unauthenticated modification of payment status via the vulnerable submission_id parameter.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate Fluent Forms to version 6.1.22 or later which includes proper authorization checks on the submission_id parameter in the Stripe SCA confirmation endpoint.
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-4160 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-4160 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data