CVE-2026-5396: The Fluent Forms plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key in all versions up to, and including, 6.1.21. ...

Description

The Fluent Forms plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key in all versions up to, and including, 6.1.21. This is due to the SubmissionPolicy class authorizing submission-level actions (read, modify, delete, add notes) based on a user-supplied `form_id` query parameter. This makes it possible for authenticated attackers, with Fluent Forms Manager access restricted to specific forms, to read, modify status, add notes to, and permanently delete form submissions belonging to any other form by spoofing the form_id parameter to a form they are authorized for.

Metrics

CVSS 3.1

8.2/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

EPSS Probability

0.22%

12.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-639

References

Timeline

Published: May 14, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-5396?

The Fluent Forms plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key in all versions up to, and including, 6.1.21. This is due to the SubmissionPolicy class authorizing submission-level actions (read, modify, delete, add notes) based on a user-supplied `form_id` query parameter. This makes it possible for authenticated attackers, with Fluent Forms Manager access restricted to specific forms, to read, modify status, add notes to, and permanently delete form submissions belonging to any other form by spoofing the form_id parameter to a form they are authorized for.

How severe is CVE-2026-5396?

CVE-2026-5396 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2026-5396?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.