High 8.8Published Oct 30, 2026

CVE-2026-89435Formidable Forms <= 6.35 - Authenticated (Subscriber+) Arbitrary Plugin Installation via 'file_url' Parameter

Updated under an hour ago (Oct 30, 2026, 5:50 AM ET)

Does this affect you?

It affects strategy11team Formidable Forms – Contact Form, Survey, Quiz, Payment, Calculator Form & Custom Form Builder. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Start free and add your stackFree account, 3 products Every CVE for strategy11team Formidable Forms – Contact Form, Survey, Quiz, Payment, Calculator Form & Custom Form Builder Exploited in the last 30 days

The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More plugin for WordPress is vulnerable to Arbitrary Plugin Installation in all versions up to, and including, 6.35 via the 'file_url' parameter parameter. This is due to insufficient URL prefix validation in validate_url_is_in_s3_bucket() and a permission callback that relies solely on a shared token obtainable by any user with the delegable frm_view_forms capability, without checking install_plugins or activate_plugins capabilities. This makes it possible for authenticated attackers, with subscriber-level access and above, to install arbitrary plugins on the server. Exploitation additionally requires that the site is free-only (Formidable Pro is NOT installed).

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-74
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Wordfence
NVD analysis: Received
Record last updated: Oct 30, 2026
First seen by InfoSec Signals: Oct 30, 2026

Affected products

Affected products

strategy11team Formidable Forms – Contact Form, Survey, Quiz, Payment, Calculator Form & Custom Form Builder strategy11team:formidable_forms_contact_form_survey_quiz_payment_calculator_form_and_custom_form_builder (from the name)	through 6.35	CNA record

References

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/87661de6-e835-495e-9bd2-4d64b4718108?source=cve
https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1514
https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1489
https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/helpers/FrmAppHelper.php#L4934
https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1459
https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAppController.php#L1167
https://plugins.trac.wordpress.org/changeset?reponame=&new=3750372%40formidable%2Ftags%2F7.0&old=3688662%40formidable%2Ftags%2F6.35
https://plugins.trac.wordpress.org/changeset/3746820/formidable/trunk/classes/controllers/FrmAddonsController.php

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.