CVE-2026-89435
Formidable Forms <= 6.35 - Authenticated (Subscriber+) Arbitrary Plugin Installation via 'file_url' Parameter
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).
| CWE | CWE-74 |
| Vendor | strategy11team |
| Product | formidable forms – contact form, survey, quiz, payment, calculator form & custom form builder |
| Published | Oct 30, 2026 |
| Last Updated | Oct 30, 2026 |
Get instant alerts for strategy11team formidable forms – contact form, survey, quiz, payment, calculator form & custom form builder
Be the first to know when new high vulnerabilities affecting strategy11team formidable forms – contact form, survey, quiz, payment, calculator form & custom form builder are published — delivered to Slack, Telegram or Discord.
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H