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CVE-2026-19807 — The ByteCoreStack – MCP Connector for AI Tools plugin for WordPress is vulnerable to…

Key facts

CVE-2026-19807 is a High (8.8) vulnerability: The ByteCoreStack – MCP Connector for AI Tools plugin for WordPress is vulnerable to…. This entry ships a detection-only PoC and a Docker test lab.
CVE CVE-2026-19807
Severity High (8.8)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-19807/

Details

English | 한국어

Description

The ByteCoreStack – MCP Connector for AI Tools plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.3 This is due to the wp_update_user_meta MCP tool in execute_tool gating writes solely with current_user_can('edit_user', $uid) — a check that WordPress core's map_meta_cap resolves to the read primitive when the target user ID matches the caller's own — while enforcing an incomplete meta key blocklist that covers only user_pass, user_activation_key, and session_tokens, leaving the wp_capabilities and wp_user_level meta keys entirely unprotected. This makes it possible for authenticated attackers with Subscriber-level access and above to elevate their privileges to Administrator by issuing a wp_update_user_meta call over the MCP JSON-RPC endpoint with key=wp_capabilities and an arbitrary role array such as {'administrator': true} targeting their own user ID, causing WordPress to load that account as an Administrator on the next request.

Vulnerability Details

Property Value
CVE ID CVE-2026-19807
CVSS Score 8.8

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-19807/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-2026-19807

# 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/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2042
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2044
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2046
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L332
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/OAuth/Server.php#L122
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2042
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2044
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2046
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L332
  • https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/OAuth/Server.php#L122
  • https://plugins.trac.wordpress.org/changeset/3711908/bcs-mcp-manager/trunk/includes/MCP/Server.php
  • https://plugins.trac.wordpress.org/changeset?reponame=&new=3711909%40bcs-mcp-manager%2Ftags%2F1.2.4&old=3711721%40bcs-mcp-manager%2Ftags%2F1.2.3
  • https://www.wordfence.com/threat-intel/vulnerabilities/id/ac09bf3e-49cf-4f11-92ba-d1fbf6f587d7?source=cve

Generated by PoC Generator on 2026-10-04T06:11:56.830235426

Frequently asked questions

What is CVE-2026-19807?

CVE-2026-19807 is a High (8.8) vulnerability: The ByteCoreStack – MCP Connector for AI Tools plugin for WordPress is vulnerable to…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-19807?

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-2026-19807?

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.