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Vulnerabilities and Security Researches

Formidable Forms – Contact Form, Survey, Quiz, Payment, Calculator Form & Custom Form Builder, CVE-2026-2890

CVE, Research URL

CVE-2026-2890

Published on
Mar 14, 2026
Research Description
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.
Affected versions
max 6.29.
Status
vulnerable