CVE-2026-2888: medium-severity vulnerability in strategy11team Formidable Forms – Contact Form…
Formidable Forms <= 6.28 - Unauthenticated Payment Amount Manipulation via 'item_meta' Parameter
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.4%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Affected products
strategy11team · Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form BuilderRelated CVEs — strategy11team Formidable Forms – Contact Form…
In the same product, most dangerous first.
CVE-2017-20194MEDIUMFormidable Form Builder < 2.05.03 - Unauthenticated Information DisclosureEPSS 1.1%CVE-2017-20192HIGHFormidable Form Builder < 2.05.03 - Unauthenticated Stored Cross-Site ScriptingEPSS 1.1%CVE-2024-11188MEDIUMFormidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder <= 6.16.1.2 - Reflected Cross-Site Scripting via Custom HTML Form ParameterEPSS 0.4%CVE-2023-6830MEDIUMFormidable Forms <= 6.7 - HTML InjectionEPSS 0.4%CVE-2024-6725MEDIUMFormidable Forms <= 6.11.1 - Authenticated (Subscriber+) Stored Cross-Site ScriptingEPSS 0.4%CVE-2026-2890HIGHFormidable Forms <= 6.28 - Missing Authorization to Unauthenticated Payment Integrity Bypass via PaymentIntent ReuseEPSS 0.4%
References
https://plugins.trac.wordpress.org/browser/formidable/tags/6.28/stripe/controllers/FrmStrpLiteHooksController.php#L88https://plugins.trac.wordpress.org/browser/formidable/tags/6.28/stripe/models/FrmStrpLiteAuth.php#L322https://plugins.trac.wordpress.org/browser/formidable/tags/6.28/stripe/models/FrmStrpLiteAuth.php#L402https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3480574%40formidable%2Ftrunk&old=3460198%40formidable%2Ftrunk&sfp_email=&sfph_mail=https://www.wordfence.com/threat-intel/vulnerabilities/id/b8be3b6e-a035-4e6f-ba2b-ce9e59ebf2e0?source=cve