CVE-2026-109997 json
Ninja Forms <= 3.15.5 - Unauthenticated Stored Cross-Site Scripting via 'extra' Parameter via Metadata Key Normalization
published 9d ago modified 7d ago also EUVD-2026-114576
- cvss
- 7.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 38%
- public exploits
- 0
- none known
Summary
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.
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 8d ago
Exploit prediction
0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
Affected products
- kstover Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/54da4deb-e50c-478d-ab99-222c5573a036?source=cve
- plugins.trac.wordpress.org /browser/ninja-forms/tags/3.15.5/includes/Templates/admin-metaboxes-calcs.html.php#L4
- plugins.trac.wordpress.org /browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L52
- plugins.trac.wordpress.org /browser/ninja-forms/tags/3.15.5/includes/AJAX/Controllers/Submission.php#L428
- plugins.trac.wordpress.org /browser/ninja-forms/tags/3.15.5/includes/Actions/Save.php#L311
- plugins.trac.wordpress.org /browser/ninja-forms/tags/3.15.5/includes/Database/Models/Submission.php#L731
- plugins.trac.wordpress.org /browser/ninja-forms/tags/3.15.5/includes/Admin/Metaboxes/Calculations.php#L23
- wordpress.org /plugins/ninja-forms/
- plugins.trac.wordpress.org /changeset/3749135/ninja-forms/trunk/includes/Templates/admin-metaboxes-calcs.html.php
Sources
- CVE List CVE-2026-109997
- NVD CVE-2026-109997
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.