Ninja Forms <= 3.15.5 — Unauthenticated Stored Cross-Site Scripting via 'extra' Parameter via Metadata Key Normalization
CVE-2026-109997Published · Updated Action summary
Affected: ≤3.15.5Update to 3.15.6 or newer
All remediation steps- Severity
- High7.2
- CVSS
- 7.2CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:NUser interaction- None
S:CScope- Changed
C:LConfidentiality- Low
I:LIntegrity- Low
A:NAvailability- None
- Weakness
- CWE-79 Cross-Site Scripting
- Required access
- No account needed
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder ninja-forms
- Affected≤ 3.15.5
- Patched in3.15.6
Update to 3.15.6 or newer.
You are affected if you run ≤ 3.15.5. Version 3.15.6 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 3.15.6, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to daroo.
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.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder
All 95| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium6.1 | Reflected DOM-Based Cross-Site Scripting via 'querystring:<key>' URL Parameter ≤3.15.5Update to 3.15.6 | CVE-2026-100151 | |
| Medium6.5 | Unauthenticated Arbitrary Shortcode Execution via 'formData' Field Value via Success Message Merge Tag ≤3.15.5Update to 3.15.6 | CVE-2026-100155 | |
| Medium5.4 | Authenticated (Subscriber+) Arbitrary Shortcode Execution via '{wp:user_display_name}' Merge Tag via display_name ≤3.15.5Update to 3.15.6 | CVE-2026-101326 | |
| Medium5.8 | Unauthenticated CSV Injection ≤3.15.3Update to 3.15.4 | CVE-2026-67187 | |
| High7.2 | Unauthenticated Stored Cross-Site Scripting ≤3.15.5Update to 3.15.6 | CVE-2026-110899 |
- Medium6.1Reflected DOM-Based Cross-Site Scripting via 'querystring:<key>' URL Parameter
≤3.15.5Update to 3.15.6
- Medium6.5Unauthenticated Arbitrary Shortcode Execution via 'formData' Field Value via Success Message Merge Tag
≤3.15.5Update to 3.15.6
- Medium5.4Authenticated (Subscriber+) Arbitrary Shortcode Execution via '{wp:user_display_name}' Merge Tag via display_name
≤3.15.5Update to 3.15.6
- Medium5.8Unauthenticated CSV Injection
≤3.15.3Update to 3.15.4
- High7.2Unauthenticated Stored Cross-Site Scripting
≤3.15.5Update to 3.15.6
Same weakness (Cross-Site Scripting)
All Cross-Site Scripting| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| High7.2 | Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header | CVE-2026-120688 | |
| Critical9.8 | Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission | CVE-2026-125055 | |
| Critical9.8 | Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter | CVE-2026-119077 | |
| Medium5.3 | Unauthenticated Sensitive Information Exposure in 'search' Parameter | CVE-2026-121518 |
- High7.2Unauthenticated Stored Cross-Site Scripting via Comment User-Agent Header
EZ SQL Reports Shortcode Widget and DB Backup
≤5.25.25Update to 5.26.45
- Critical9.8Unauthenticated Arbitrary File Upload via File Upload via Public Form Submission
Chatterbug Forms – Fast, Flexible WordPress Form Builder
≤1.0.2Update to 1.1
- Critical9.8Unauthenticated PHP Object Injection to Remote Code Execution via 'form' Parameter
ELEX WordPress HelpDesk & Customer Ticketing System
≤3.3.9Update to 3.4.0
- Medium5.3Unauthenticated Sensitive Information Exposure in 'search' Parameter
Customer Reviews for WooCommerce
≤5.127.0Update to 5.128.0
Timeline
CVE published
Severity high, CVSS 7.2
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. [object Object] Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- [object Object]. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.