CVE-2026-2890 Formidable Forms <= 6.28 - Missing Authorization to Unauthenticated Payment Integrity Bypass via PaymentIntent Reuse
Unauthenticated attackers can bypass payment verification by reusing low-value Stripe PaymentIntents to mark high-value orders as complete.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-2890?
CVE-2026-2890 is a high-severity missing authorization vulnerability in strategy11team Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder, published on 13 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-862
Which versions are affected by CVE-2026-2890?
How do I fix CVE-2026-2890?
No fix has been published for CVE-2026-2890 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-2890 being exploited?
There is no known exploitation of CVE-2026-2890 in the wild and no public exploit code.
Sources
Also known as GHSA-4rrh-wqqx-4jh2.