CVE Catalog

CVE-2026-109997

HighCVSS 7.2
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.44%

38th percentile - higher than 38% of all known CVEs

Summary

The Ninja Forms 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 allows unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Risk Assessment

An attacker could execute arbitrary JavaScript in the browsers of users visiting the affected page, potentially leading to session or data theft. The risk is high because the nf_ajax_submit endpoint issues a valid nonce to any requester on failure, neutralizing the nonce check and making exploitation trivially achievable in a single unauthenticated request.

Recommendation

Update the Ninja Forms plugin to a version later than 3.15.5. Until then, consider restricting access to the nf_ajax_submit endpoint or deploying WAF rules to block suspicious payloads in the formData.extra parameter.

Other vulnerabilities in Ninja Forms

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS