Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%

Buy Us a Coffee

CVE-2026-109997— Ninja Forms <= 3.15.5 - Unauthenticated Stored Cross-Site Scripting via 'extra' Parameter via Metadata Key Normalization

Quick assessment

Affected

kstover Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

WordPress 插件"Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder"在 3.15.5 及之前所有版本中，由于输入清理和输出转义不足，存在通过参数触发的存储型跨站脚本（Stored XSS）漏洞。该漏洞使得未认证的攻击者能够在页面中注入任意 Web 脚本，当用户访问被注入的页面时，这些脚本将被执行。此外，端点在请求失败时仍会向任何请求者返回有效的 nonce，从而实质上使 n

CVSS 7.2 · High Updated Oct 31, 2026

Possible ATT&CK Techniques 2 AI

T1059 · Command and Scripting Interpreter T1190 · Exploit Public-Facing Application

Get alerts for future matching vulnerabilities Log in to subscribe

Vulnerability Information

Have questions about the vulnerability? See if Shenlong's analysis helps!

View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title

Ninja Forms <= 3.15.5 - Unauthenticated Stored Cross-Site Scripting via 'extra' Parameter via Metadata Key Normalization

Source: CVE Program / CVE List V5

Vulnerability 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.

Source: CVE Program / CVE List V5

CVSS Information

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Source: CVE Program / CVE List V5

Vulnerability Type

在Web页面生成时对输入的转义处理不恰当(跨站脚本)

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
kstover	Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder	0 ~ 3.15.5	-

II. Public POCs for CVE-2026-109997

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2026-109997

请登录查看更多情报信息。

Vendor Pages for CVE-2026-109997 (1)

🔗 Ninja Forms – The Contact Form Builder That Grows With You – WordPress plugin | WordPress.org Read full article

Other References for CVE-2026-109997 (8)

https://www.cve.org/CVERecord?id=CVE-2026-109997

Same Patch Batch · kstover · 2026-10-31 · 3 CVEs total

CVE-2026-100155	6.5 MEDIUM	Ninja Forms <= 3.15.5 - Unauthenticated Arbitrary Shortcode Execution via 'formData' Field
CVE-2026-101326	5.4 MEDIUM	Ninja Forms <= 3.15.5 - Authenticated (Subscriber+) Arbitrary Shortcode Execution via '{wp

IV. Related Vulnerabilities

Same product: Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder

Same vendor: kstover

Same weakness: CWE-79