What’s Vulnerable › Vulnerabilities

CVE-2026-2890: Formidable Forms <= 6.28 - Missing Authorization to Unauthenticated Payment Integrity Bypass via PaymentIntent Reuse

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-13 · updated 2026-06-17
• Weakness: CWE-862

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 products

• strategy11team Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder: through 6.28

References

• https://plugins.trac.wordpress.org/browser/formidable/tags/6.28/stripe/controllers/FrmStrpLiteHooksController.php#L92
• https://plugins.trac.wordpress.org/browser/formidable/tags/6.28/stripe/controllers/FrmStrpLiteLinkController.php#L429
• https://plugins.trac.wordpress.org/browser/formidable/tags/6.28/stripe/controllers/FrmStrpLiteLinkController.php#L79
• https://www.wordfence.com/threat-intel/vulnerabilities/id/ebb4bc5a-9469-4733-acf3-d2dda5edb7af?source=cve

Get alerted when CVE-2026-2890 or the next vulnerability affects your stack