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CVE-2026-46562 — Yamcs is a mission control framework.

Key facts

CVE-2026-46562 is a Critical (9.8) vulnerability: Yamcs is a mission control framework.. This entry ships a detection-only PoC and a Docker test lab.

CVE CVE-2026-46562
Severity Critical (9.8)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-46562/

Details

English | 한국어

Description

Yamcs is a mission control framework. Prior to 5.12.7, the Nashorn ScriptEngine used to evaluate user-supplied JavaScript algorithm text in yamcs-core/src/main/java/org/yamcs/algorithms/ScriptAlgorithmExecutorFactory.java was constructed without a ClassFilter, so a user with the ChangeMissionDatabase privilege could override an algorithm through the MdbOverrideApi.updateAlgorithm endpoint and supply JavaScript that reaches arbitrary Java classes (for example Java.type("java.lang.Runtime").getRuntime().exec(...)) to execute arbitrary OS commands as the Yamcs process; in the default configuration with no security.yaml the built-in guest user has superuser=true, making the issue reachable without authentication. This issue is fixed in versions 5.12.7 and 5.13.0, which disable algorithm editing by default.

Vulnerability Details

Property Value
CVE ID CVE-2026-46562
Type RCE
CVSS Score 9.8

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-46562/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-2026-46562

# 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/yamcs/yamcs/commit/3c550348f866af4675d2ba4a51d8d12b7c7c6011
  • https://github.com/yamcs/yamcs/commit/4ff8fda642ea8c3309a4d3f379aa77b763148992
  • https://github.com/yamcs/yamcs/releases/tag/yamcs-5.12.7
  • https://github.com/yamcs/yamcs/releases/tag/yamcs-5.13.0
  • https://github.com/yamcs/yamcs/security/advisories/GHSA-vmwp-vh32-rj75
  • https://github.com/yamcs/yamcs/security/advisories/GHSA-vmwp-vh32-rj75

Generated by PoC Generator on 2026-07-17T08:28:44.269280563

Frequently asked questions

What is CVE-2026-46562?

CVE-2026-46562 is a Critical (9.8) vulnerability: Yamcs is a mission control framework.. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-46562?

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-2026-46562?

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.