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CVE-2026-15450 — The Nex Forms – Ultimate Form Builder – Lite plugin for WordPress is vulnerable to…

Key facts

CVE-2026-15450 is a High (8.1) vulnerability: The Nex Forms – Ultimate Form Builder – Lite plugin for WordPress is vulnerable to…. This entry ships a detection-only PoC and a Docker test lab.
CVE CVE-2026-15450
Severity High (8.1)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-15450/

Details

English | 한국어

Description

The Nex Forms – Ultimate Form Builder – Lite plugin for WordPress is vulnerable to arbitrary file deletion via path traversal in versions up to, and including, 9.2.3. This is due to the delete_file() AJAX handler retrieving a file path from the database and passing it directly to unlink() with no validation (no realpath(), basename(), or allowlist check), combined with the insert_record() AJAX handler that lets the same authenticated user store an arbitrary value in the target 'location' column (wp_kses() only strips HTML tags and does not neutralize path traversal or absolute paths). This makes it possible for authenticated attackers, with admin-level access and above, to delete arbitrary files on the affected site's server, including wp-config. When the plugin's user-level option is configured to something else, this may be exploitable with lower privileges.

Vulnerability Details

Property Value
CVE ID CVE-2026-15450
Type PATH_TRAVERSAL
CVSS Score 8.1

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-15450/poc.py

Usage

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start

# Clone and navigate to CVE directory
cd CVE-2026-15450

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints

Application URL Status
Vulnerable App http://localhost:8080 Shows vulnerability
Patched App http://localhost:8081 Demonstrates fix

Directory Structure

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References

  • https://plugins.trac.wordpress.org/browser/nex-forms-express-wp-form-builder/tags/9.2.3/includes/classes/class.db.php#L269
  • https://plugins.trac.wordpress.org/browser/nex-forms-express-wp-form-builder/tags/9.2.3/includes/classes/class.db.php#L273
  • https://plugins.trac.wordpress.org/browser/nex-forms-express-wp-form-builder/tags/9.2.3/includes/classes/class.db.php#L805
  • https://plugins.trac.wordpress.org/changeset?reponame=&old=3625615%40nex-forms-express-wp-form-builder&new=3625615%40nex-forms-express-wp-form-builder
  • https://www.wordfence.com/threat-intel/vulnerabilities/id/bb5c8cb3-df67-4f2c-869a-48e34f5619ff?source=cve

Generated by PoC Generator on 2026-08-01T20:57:49.380475599

Frequently asked questions

What is CVE-2026-15450?

CVE-2026-15450 is a High (8.1) vulnerability: The Nex Forms – Ultimate Form Builder – Lite plugin for WordPress is vulnerable to…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-15450?

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2026-15450?

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

For authorized security testing and research only. See the full source and NVD record.