CVE-2026-100844 — MONAI before 1.6.0 is vulnerable to OS command injection in the nnUNetV2Runner component…¶

Key facts

CVE-2026-100844 is a High (8.4) vulnerability: MONAI before 1.6.0 is vulnerable to OS command injection in the nnUNetV2Runner component…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-100844
Severity	High (8.4)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-100844/

Details¶

English | 한국어

Description¶

MONAI before 1.6.0 is vulnerable to OS command injection in the nnUNetV2Runner component (monai.apps.nnunet.nnunetv2_runner). User-controlled values taken from the YAML configuration file (notably dataset_name_or_id) and from CLI/kwargs arguments are concatenated into a command string without quoting or validation and then passed to subprocess with shell=True, so shell metacharacters (e.g., ';' on Linux, '&' on Windows) are interpreted. If a victim loads and processes a crafted configuration file — for example by instantiating nnUNetV2Runner with the malicious YAML and invoking a training/validation job such as train_single_model() — arbitrary commands are executed with the privileges of the user running the job.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-100844
Type	RCE
CVSS Score	8.4

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-100844/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-2026-100844

# 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/Project-MONAI/MONAI/security/advisories/GHSA-rghg-q7wp-9767
https://www.vulncheck.com/advisories/monai-before-1.6.0-os-command-injection-via-dataset-name-or-id

Generated by PoC Generator on 2026-09-27T13:19:54.382807433

Frequently asked questions¶

What is CVE-2026-100844?¶

CVE-2026-100844 is a High (8.4) vulnerability: MONAI before 1.6.0 is vulnerable to OS command injection in the nnUNetV2Runner component…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-100844?¶

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-2026-100844?¶

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.