dbcve.org
Authorization Bypass (IDOR)Weakness · CWE-639

CVE-2026-2888

MEDIUM · 5.3 CVSS v3.1 Published 2026-03-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

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 · unedited
The Formidable Forms plugin for WordPress is vulnerable to an authorization bypass through user-controlled key in all versions up to, and including, 6.28. This is due to the `frm_strp_amount` AJAX handler (`update_intent_ajax`) overwriting the global `$_POST` data with attacker-controlled JSON input and then using those values to recalculate payment amounts via field shortcode resolution in `generate_false_entry()`. The handler relies on a nonce that is publicly exposed in the page's JavaScript (`frm_stripe_vars.nonce`), which provides CSRF protection but not authorization. This makes it possible for unauthenticated attackers to manipulate PaymentIntent amounts before payment completion on forms using dynamic pricing with field shortcodes, effectively paying a reduced amount for goods or services.

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 confidence

The Formidable Forms plugin's Stripe payment AJAX handler (`update_intent_ajax`) accepts attacker-controlled JSON input that overwrites `$_POST` data and uses it to recalculate payment amounts via field shortcode resolution. The nonce used for CSRF protection is publicly exposed in JavaScript, providing no authorization check. This allows unauthenticated attackers to manipulate PaymentIntent amounts on forms using dynamic pricing with field shortcodes.

MitigationUpdate to plugin version 6.29 or later which contains the vendor patch. Alternatively, disable dynamic pricing with field shortcodes in Stripe-enabled forms until the update can be applied.

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 checks

Work through these to decide whether this CVE applies to you.

  1. Verify Formidable Forms plugin is installed
    Check your WordPress plugins directory or use wp-cli: `wp plugin list --name=formidable` to see if Formidable Forms is active and note the installed version
    Affected if Plugin version is present and below 6.29 (the fixed version)
  2. Confirm Stripe payment module is active
    Navigate to Formidable > Stripe Payments in the WordPress admin dashboard, or check for the presence of the Stripe integration files in /wp-content/plugins/formidable-stripe/ or within the main Formidable plugin
    Affected if Stripe module is enabled and connected to any form
  3. Identify forms using dynamic pricing with field shortcodes
    Review forms that have Stripe payment enabled. Look for form fields containing shortcodes in payment amount calculations (e.g., [frm-field-value field_id=X], [field id=X], or other dynamic field shortcodes used in pricing fields)
    Affected if Any form uses Stripe payments with dynamic pricing that resolves field shortcodes for amount calculation
  4. Check the AJAX handler availability
    Verify the endpoint /wp-admin/admin-ajax.php?action=update_intent_ajax is accessible. This can be tested via curl: `curl -s -X POST https://yourdomain.com/wp-admin/admin-ajax.php -d 'action=update_intent_ajax' -d 'nonce=anyvalue'`. A vulnerable site will respond without rejecting the request
    Affected if The AJAX handler responds and accepts requests without proper authorization validation

A user is affected if they have Formidable Forms installed with Stripe payments enabled, are running a version below 6.29, and have forms using dynamic pricing with field shortcodes in payment calculations.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to plugin version 6.29 or later which contains the vendor patch. Alternatively, disable dynamic pricing with field shortcodes in Stripe-enabled forms until the update can be applied.

Recommended fix Moderate confidence

Formidable Forms version 6.28.1 or later (next stable release after 6.28)

  1. 1. Identify all WordPress sites using the Formidable Forms plugin with Stripe integration and dynamic pricing.
  2. 2. Check the currently installed version of Formidable Forms (in WordPress admin under Plugins).
  3. 3. If the installed version is 6.28 or earlier, prepare to upgrade.
  4. 4. Before upgrading, backup the WordPress database and files.
  5. 5. Upgrade the Formidable Forms plugin to the latest available version from the WordPress plugin repository.
  6. 6. Verify the upgrade was successful and test Stripe payment functionality with dynamic pricing forms.
  7. 7. Confirm the `update_intent_ajax` handler now properly validates user authorization before allowing payment amount manipulation.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-2888 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-2888 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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