CVE-2026-109997

HIGH
MEDIUM Priority: 0.03 BB Relevance: 74/100
Published: 2026-10-31 Modified: 2026-10-31 First seen: 2026-10-31 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Scope Change

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Changed
C: Low
I: Low
A: None

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.

Bug Bounty Relevance

74 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

7.2 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

EPSS — Exploitation Probability

0.44%
Raw Score 0.004420
Percentile 38.5%
Date 2026-10-31

Intelligence Sources

mitre ref →
nvd ref →