CVE-2026-89435: strategy11team Formidable Forms – Contact Form, Survey, Quiz, Payment, Calculator Form & Custom Form Builder (High, CVSS 8.8)
- CVSS
- 8.8 High (v3.1)
- EPSS
- 0.4% chance of exploitation in the next 30 days (higher than 33.3% of CVEs)
- Exploited in the wild
- Not on CISA’s KEV list
- Public exploit
- None reported in public exploit databases
- Weakness
- CWE-74
- Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H- Published
- Oct 30, 2026
What it is
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).
Description from the National Vulnerability Database.
What to do
Check whether you run strategy11team Formidable Forms – Contact Form, Survey, Quiz, Payment, Calculator Form & Custom Form Builder, then apply the vendor’s fix or mitigation from the advisories below.
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.