CVE-2026-105857 — Payload is a free and open source headless content management system.¶

Key facts

CVE-2026-105857 is a Critical (10.0) vulnerability: Payload is a free and open source headless content management system.. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-105857
Severity	Critical (10.0)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-105857/

Details¶

English | 한국어

Description¶

Payload is a free and open source headless content management system. In @payloadcms/plugin-form-builder versions before 3.90.0 and canary versions before 4.0.0-canary.34, an attacker can craft a form submission that executes code remotely on the server. This issue is fixed in versions 3.90.0 and 4.0.0-canary.34.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-105857
Type	RCE
CVSS Score	10.0

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-105857/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-2026-105857

# 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/payloadcms/payload/commit/333b82b9f3e685fed6826c2e3270da79df8336c6
https://github.com/payloadcms/payload/releases/tag/v3.90.0
https://github.com/payloadcms/payload/security/advisories/GHSA-r488-j9vj-wx3q

Generated by PoC Generator on 2026-10-08T19:43:57.24721164

Frequently asked questions¶

What is CVE-2026-105857?¶

CVE-2026-105857 is a Critical (10.0) vulnerability: Payload is a free and open source headless content management system.. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-105857?¶

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-2026-105857?¶

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.