# CVE-2026-109997: CVE-2026-109997

Status: published. Published: 2026-10-31. Updated: 2026-11-01.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

Not reported in collected sources.

## Severity and prioritization

- CVSS 3.1: 7.2 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N; source: NVD: security@wordfence.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: exploitation none; automatable no; technical impact partial; source NVD SSVC: 134c704f-9b21-4f2e-91b3-4a467353bcc0

- Weaknesses: CWE-79

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L428 (security@wordfence.com)

- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L52 (security@wordfence.com)

- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Actions/Save.php#L311 (security@wordfence.com)

- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Admin/Metaboxes/Calculations.php#L23 (security@wordfence.com)

- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Database/Models/Submission.php#L731 (security@wordfence.com)

- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Templates/admin-metaboxes-calcs.html.php#L4 (security@wordfence.com)

- https://plugins.trac.wordpress.org/changeset/3749135/ninja-forms/trunk/includes/Templates/admin-metaboxes-calcs.html.php (security@wordfence.com)

- https://wordpress.org/plugins/ninja-forms/ (security@wordfence.com)

- https://www.wordfence.com/threat-intel/vulnerabilities/id/54da4deb-e50c-478d-ab99-222c5573a036?source=cve (security@wordfence.com)

## Provenance

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-109997; retrieved 2026-11-02; source updated 2026-11-01

Revision: 824068c18274f233aca0b5f8c5a977af2dd880a6bcd31bf8471da169efd2121d

Canonical: https://y2.dev/cve/CVE-2026-109997