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CVE-2026-105123 — W (vincent-peugnet/wcms) through 3.18.0 contains a remote code execution vulnerability…

Key facts

CVE-2026-105123 is a High (8.8) vulnerability: W (vincent-peugnet/wcms) through 3.18.0 contains a remote code execution vulnerability…. This entry ships a detection-only PoC and a Docker test lab.

CVE CVE-2026-105123
Severity High (8.8)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-105123/

Details

English | 한국어

Description

W (vincent-peugnet/wcms) through 3.18.0 contains a remote code execution vulnerability that allows authenticated editors to write arbitrary files by abusing the unvalidated path in POST /api/v0/media/upload/[:path]. Attackers can upload .php files executed by the web server, use encoded ../ sequences to write outside the media directory, and delete arbitrary files via DELETE /api/v0/media/[:path].

Vulnerability Details

Property Value
CVE ID CVE-2026-105123
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-2026-105123/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-2026-105123

# 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://github.com/vincent-peugnet/wcms
  • https://github.com/vincent-peugnet/wcms/blob/cda5bcdb95dbdb1e804fdfe0e5fd2e2b2f8a90e2/app/class/Controllerapimedia.php#L24-L44
  • https://github.com/vincent-peugnet/wcms/blob/cda5bcdb95dbdb1e804fdfe0e5fd2e2b2f8a90e2/app/class/Media.php#L98
  • https://github.com/vincent-peugnet/wcms/issues/662
  • https://www.vulncheck.com/advisories/w-wcms-through-3.18.0-rce-and-arbitrary-file-write-via-media-upload-api

Generated by PoC Generator on 2026-10-04T10:45:21.028600274

Frequently asked questions

What is CVE-2026-105123?

CVE-2026-105123 is a High (8.8) vulnerability: W (vincent-peugnet/wcms) through 3.18.0 contains a remote code execution vulnerability…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-105123?

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-2026-105123?

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.