{"id":"CVE-2026-89435","aliases":["EUVD-2026-113736","GHSA-7366-rqfr-5w7j"],"status":"published","title":"Formidable Forms \u003c= 6.35 - Authenticated (Subscriber+) Arbitrary Plugin Installation via 'file_url' Parameter","description":"The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes \u0026 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).","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00392,"percentile":0.3366,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-74"],"published":"2026-10-30T06:47:31Z","modified":"2026-10-30T19:20:18Z","products":[{"vendor":"sswells","product":"formidable forms – contact form, survey, quiz, payment, calculator form \u0026 custom form builder"},{"vendor":"strategy11team","product":"formidable forms – contact form, survey, quiz, payment, calculator form \u0026 custom form builder"}],"references":[{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/87661de6-e835-495e-9bd2-4d64b4718108?source=cve"},{"url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1514"},{"url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1489"},{"url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/helpers/FrmAppHelper.php#L4934"},{"url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAddonsController.php#L1459"},{"url":"https://plugins.trac.wordpress.org/browser/formidable/tags/6.35/classes/controllers/FrmAppController.php#L1167"},{"url":"https://plugins.trac.wordpress.org/changeset?reponame=\u0026new=3750372%40formidable%2Ftags%2F7.0\u0026old=3688662%40formidable%2Ftags%2F6.35"},{"url":"https://plugins.trac.wordpress.org/changeset/3746820/formidable/trunk/classes/controllers/FrmAddonsController.php"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89435"},{"url":"https://github.com/advisories/GHSA-7366-rqfr-5w7j"}],"sources":{"cve":[{"id":"CVE-2026-89435","title":"Formidable Forms \u003c= 6.35 - Authenticated (Subscriber+) Arbitrary Plugin Installation via 'file_url' Parameter","description":"The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes \u0026 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).","status":"published","published":"2026-10-30T06:47:31.045Z","modified":"2026-10-30T18:09:00.504Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-74"],"updated_at":"2026-11-02T14:19:55.176387Z"}],"euvd":[{"id":"EUVD-2026-113736","description":"The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes \u0026 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).","status":"published","published":"2026-10-30T06:47:31Z","modified":"2026-10-30T18:09:00Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T16:59:03.071815Z"}],"ghsa":[{"id":"GHSA-7366-rqfr-5w7j","title":"The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes \u0026 More...","description":"The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes \u0026 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).","status":"published","published":"2026-10-30T09:31:25Z","modified":"2026-10-30T09:31:25Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-74"],"updated_at":"2026-11-02T15:14:41.74258Z"}],"nvd":[{"id":"CVE-2026-89435","description":"The Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes \u0026 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).","status":"published","published":"2026-10-30T07:16:34.41Z","modified":"2026-10-30T19:20:18.44Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-74"],"updated_at":"2026-11-02T14:13:04.940026Z"}]}}