Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder

The Formidable Forms plugin for WordPress is vulnerable to a payment integrity bypass in all versions up to, and including, 6.28. This is due to the Stripe Link return handler (`handle_one_time_stripe_link_return_url`) marking payment records as complete based solely on the Stripe PaymentIntent status without comparing the intent's charged amount against the expected payment amount, and the `verify_intent()` function validating only client secret ownership without binding intents to specific forms or actions. This makes it possible for unauthenticated attackers to reuse a PaymentIntent from a completed low-value payment to mark a high-value payment as complete, effectively bypassing payment for goods or services.

Published: 2026-03-13T07:23:39.586Z
Updated: 2026-04-08T17:31:16.361Z

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.

Published: 2026-03-13T08:25:17.249Z
Updated: 2026-04-08T17:17:50.074Z

The Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘html’ parameter in all versions up to, and including, 6.11.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with form editing permissions and Subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Published: 2024-07-31T10:59:17.745Z
Updated: 2026-04-08T17:04:25.840Z

The Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder plugin for WordPress is vulnerable to POST-Based Reflected Cross-Site Scripting via the Custom HTML Form parameters in all versions up to, and including, 6.16.1.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

Published: 2024-11-23T05:40:11.211Z
Updated: 2026-04-08T17:27:21.112Z

The Formidable Forms – Contact Form, Survey, Quiz, Payment, Calculator Form & Custom Form Builder plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 6.7.2. This is due to missing or incorrect nonce validation on the update_settings function. This makes it possible for unauthenticated attackers to change form settings and add malicious JavaScript via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Published: 2024-02-05T21:21:59.377Z
Updated: 2026-04-08T17:18:03.996Z