The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to Stored…
CVE-2026-109997
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 nfajaxsubmit 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.
Assessment
- CVSS
- 7.2 (v3.1)
- Severity
- High
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 31 October 2026
- Last updated
- 31 October 2026
- Affected
- kstover
- Assigner
- Wordfence
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
At the source
References
- https://www.wordfence.com/threat-intel/vulnerabilities/id/54da4deb-e50c-478d-ab99-222c5573a036?source=cve
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Templates/admin-metaboxes-calcs.html.php#L4
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L52
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L428
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Actions/Save.php#L311
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Database/Models/Submission.php#L731
- https://plugins.trac.wordpress.org/browser/ninja-forms/tags/3.15.5/includes/Admin/Metaboxes/Calculations.php#L23
- https://wordpress.org/plugins/ninja-forms/
- https://plugins.trac.wordpress.org/changeset/3749135/ninja-forms/trunk/includes/Templates/admin-metaboxes-calcs.html.php
Community proofs of concept
No community proof of concept yet. If you have one for a published vulnerability and the right to share it, add it below — it will appear here once reviewed.
Submit a proof of concept
Only for publicly disclosed vulnerabilities, and only material from testing you were authorised to perform. This platform does not buy, sell, or broker exploits — see earning from vulnerability research for legitimate bounty programs. Submissions are reviewed before they appear. Text only; do not include live credentials, personal data, or anything targeting systems you are not permitted to test.
Query this programmatically
Agents can read this through the MCP endpoint, or over HTTP:
curl https://cve.zerocrew.in/api/cve/CVE-2026-109997