Formidable Forms <= 6.28 - Unauthenticated Payment Amount Manipulation via 'item_meta' Parameter
| CVE | CVE-2026-2888 |
|---|---|
| CVSS | 5.3 (Medium) |
| Publicly Published | March 12, 2026 |
| Last Updated | March 13, 2026 |
| Researcher |
Michael Iden (Mickhat)
- Hack The Box
|
Description
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.
References
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
- plugins.trac.wordpress.org
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Vulnerability Details for Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More
| Software Type | Plugin |
|---|---|
| Software Slug | formidable (view on wordpress.org) |
| Patched? | Yes |
| Remediation | Update to version 6.29, or a newer patched version |
| Affected Version |
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| Patched Version |
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Recent vulnerabilities in Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More
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