Ninja Forms <= 3.15.5 - Unauthenticated Stored Cross-Site Scripting via Submission 'calculations' Extra Data
- ID
- WPSEC-2026-1133
- Plugin
- Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder (ninja-forms)
- Affected
- all versions before 3.15.6
- Remediation
- Update to 3.15.6 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- Weakness
- CWE-79
- Usage
- Plugin Medium · Affected versions Medium among sites WPSec scans, 2026-10-16
- Attack surface
- Ninja Forms on WPSec AttackSurface
- Fix released
- Published
Description
The Ninja Forms plugin for WordPress is vulnerable to Stored Cross-Site Scripting via submission extra data in all versions up to, and including, 3.15.5. This is due to an incomplete check on the reserved, server-generated 'calculations' extra-data key and missing output escaping of calculation names in the admin submission Calculations metabox. The plugin removes only an exact 'calculations' key. A key containing a backslash passes that check, and update_post_meta() then unslashes it to 'calculations'. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute whenever an administrator views the affected submission.
References
- https://wpsec.com/vuln/WPSEC-2026-1133/
- https://plugins.svn.wordpress.org/ninja-forms/tags/3.15.6/
- https://wordpress.org/plugins/ninja-forms/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
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