---
id: "CVE-2026-100155"
kind: "vulnerability"
aliases: ["CVE-2026-100155"]
title: "Ninja Forms WordPress plugin: unauthenticated attackers can run arbitrary shortcodes"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ninja-forms", "package", "self-hosted", "wordpress"]
not_affected_if: ["newer-version", "plugin-not-installed"]
published_at: "2026-10-31T06:16:29+00:00"
first_seen_at: "2026-10-31T06:33:49+00:00"
updated_at: "2026-10-31T06:34:19+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-100155", "first_seen_at": "2026-10-31T06:33:49+00:00"}]
---

# Ninja Forms WordPress plugin: unauthenticated attackers can run arbitrary shortcodes

The Ninja Forms contact form plugin for WordPress passes an unvalidated value to do_shortcode, so an action can be triggered that runs arbitrary shortcodes. An unauthenticated attacker can exploit this on any site running a vulnerable version, with impact depending on which shortcodes the site has available.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Ninja Forms plugin version in the WordPress admin under Plugins, or with `wp plugin get ninja-forms --field=version`
- Compare the installed version against the affected range: all versions up to and including `3.15.5`

## Timeline

- 2026-10-31T06:33:49+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-100155

## From the sources

The The Ninja Forms – Contact Form Builder with Calculators, Quizzes, Signatures & AI Form Builder plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 3.15.5 This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for unauthenticated attackers to execute arbitrary shortcodes.

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