{"id":"CVE-2026-89435","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-89435","summary":"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,…","details":"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).","published":"2026-10-30T07:16:34.410","modified":"2026-10-30T07:16:34.410","cvss":{"score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1459"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1489"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1514"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAppController.php#L1167"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/helpers/FrmAppHelper.php#L4934"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/changeset/3746820/formidable/trunk/classes/controllers/FrmAddonsController.php"},{"type":"WEB","url":"https://plugins.trac.wordpress.org/changeset?reponame=&new=3750372%40formidable%2Ftags%2F7.0&old=3688662%40formidable%2Ftags%2F6.35"},{"type":"WEB","url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/87661de6-e835-495e-9bd2-4d64b4718108?source=cve"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-10-30T07:16:34.410"}}