strategy11team Formidable Forms Plugin up to 6.35 on WordPress Permission Callback validate_url_is_in_s3_bucket file_url permission

Summaryinfo

A vulnerability has been found in strategy11team Formidable Forms Plugin up to 6.35 and classified as critical. The impacted element is the function validate_url_is_in_s3_bucket of the component Permission Callback. The manipulation of the argument file_url leads to permission. This vulnerability is listed as CVE-2026-89435. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in strategy11team Formidable Forms Plugin up to 6.35 and classified as critical. This issue affects the function validate_url_is_in_s3_bucket of the component Permission Callback. The manipulation of the argument file_url with an unknown input leads to a permission vulnerability. Using CWE to declare the problem leads to CWE-275. Impacted is confidentiality, integrity, and availability. The summary by CVE 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).

It is possible to read the advisory at wordfence.com. The identification of this vulnerability is CVE-2026-89435 since 09/11/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/30/2026). The attack technique deployed by this issue is T1222 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• strategy11team

Name

• Formidable Forms Plugin

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6
• 6.7
• 6.8
• 6.9
• 6.10
• 6.11
• 6.12
• 6.13
• 6.14
• 6.15
• 6.16
• 6.17
• 6.18
• 6.19
• 6.20
• 6.21
• 6.22
• 6.23
• 6.24
• 6.25
• 6.26
• 6.27
• 6.28
• 6.29
• 6.30
• 6.31
• 6.32
• 6.33
• 6.34
• 6.35

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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CVSSv3info

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Entryinfo

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