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CVE-2026-19887 — The Welcart e-Commerce plugin for WordPress is vulnerable to PHP Object Injection in all…

Key facts

CVE-2026-19887 is a High (8.8) vulnerability: The Welcart e-Commerce plugin for WordPress is vulnerable to PHP Object Injection in all…. This entry ships a detection-only PoC and a Docker test lab.
CVE CVE-2026-19887
Severity High (8.8)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-19887/

Details

English | 한국어

Description

The Welcart e-Commerce plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 2.12.1 via deserialization of untrusted input in the Telecom EDY payment callback (usces_action_acting_transaction). Unauthenticated attackers can store arbitrary 'reserve' key/value pairs as order metadata during a public checkout, then invoke the callback with an attacker-chosen 'option' parameter to select and unserialize that metadata without any provider signature, source-address, transaction-identity or ownership check. A POP chain is present in the TCPDF library bundled with the plugin itself, so no additional plugin or theme is required. This makes it possible for unauthenticated attackers to delete arbitrary files on the server, including wp-config.php, which can lead to remote code execution when an attacker re-runs the WordPress installer against a database they control. Successful exploitation is contingent on an admin printing an invoice to trigger file deletion.

Vulnerability Details

Property Value
CVE ID CVE-2026-19887
Type RCE
CVSS Score 8.8

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-19887/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-2026-19887

# 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/usc-e-shop/trunk/classes/cart.class.php#L546
  • https://plugins.trac.wordpress.org/browser/usc-e-shop/trunk/classes/orderData.class.php#L41
  • https://plugins.trac.wordpress.org/browser/usc-e-shop/trunk/functions/function.php#L218
  • https://plugins.trac.wordpress.org/browser/usc-e-shop/trunk/functions/hoock_func.php#L517
  • https://plugins.trac.wordpress.org/browser/usc-e-shop/trunk/includes/order_print.php#L16
  • https://plugins.trac.wordpress.org/browser/usc-e-shop/trunk/pdf/tcpdf/tcpdf.php#L7794
  • https://plugins.trac.wordpress.org/changeset/3673344/usc-e-shop/trunk/classes/orderData.class.php
  • https://plugins.trac.wordpress.org/changeset?old_path=%2Fusc-e-shop/tags/2.12.1&new_path=%2Fusc-e-shop/tags/2.12.2
  • https://plugins.trac.wordpress.org/changeset?reponame=&new=3673346%40usc-e-shop%2Ftags%2F2.12.2&old=3651925%40usc-e-shop%2Ftags%2F2.12.1
  • https://www.wordfence.com/threat-intel/vulnerabilities/id/716a7c3c-2e26-4da9-a299-7dcbaa7e4895?source=cve

Generated by PoC Generator on 2026-09-06T00:35:09.479998138

Frequently asked questions

What is CVE-2026-19887?

CVE-2026-19887 is a High (8.8) vulnerability: The Welcart e-Commerce plugin for WordPress is vulnerable to PHP Object Injection in all…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-19887?

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-2026-19887?

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.