The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'formData.extra' parameter in all versions up to, and including, 3.15.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The nf_ajax_submit endpoint issues a valid nonce to any requester on failure, effectively neutralizing the nonce check and making exploitation trivially achievable in a single unauthenticated request.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
kstover Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder unaffected
Version Status Constraints
0 affected ≤ 3.15.5

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L428 cve-icon
https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L52 cve-icon
https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Actions/Save.php#L311 cve-icon
https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Admin/Metaboxes/Calculations.php#L23 cve-icon
https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Database/Models/Submission.php#L731 cve-icon
https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Templates/admin-metaboxes-calcs.html.php#L4 cve-icon
https://plugins.trac.wordpress.org/changeset/3749135/ninja-forms/trunk/includes/Templates/admin-metaboxes-calcs.html.php cve-icon
https://wordpress.org/plugins/ninja-forms/ cve-icon
https://www.wordfence.com/threat-intel/vulnerabilities/id/54da4deb-e50c-478d-ab99-222c5573a036?source=cve cve-icon
History

Sat, 31 Oct 2026 05:45:00 +0000

Type Values Removed Values Added
Description The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'formData.extra' parameter in all versions up to, and including, 3.15.5 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The nf_ajax_submit endpoint issues a valid nonce to any requester on failure, effectively neutralizing the nonce check and making exploitation trivially achievable in a single unauthenticated request.
Title Ninja Forms <= 3.15.5 - Unauthenticated Stored Cross-Site Scripting via 'extra' Parameter via Metadata Key Normalization
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-10-31T05:33:07.391Z

Reserved: 2026-10-13T13:34:43.127Z

Link: CVE-2026-109997

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses