CVE-2026-46621 — Yamcs is a mission control framework.¶
Key facts
CVE-2026-46621 is a Critical (9.1) vulnerability: Yamcs is a mission control framework.. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-46621 |
| Severity | Critical (9.1) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-46621/ |
Details¶
English | 한국어
Description¶
Yamcs is a mission control framework. Prior to 5.12.7, the Yamcs script evaluation engine for Python algorithms dynamically compiled and evaluated user-controlled algorithm text using Jython through the JSR-223 ScriptEngine API without enforcing a secure sandbox, so an authenticated user with the ChangeMissionDatabase privilege could override an existing Python algorithm's logic through the mission database REST API and import and execute arbitrary Java classes such as java.lang.Runtime to achieve remote code execution on the underlying host operating system. 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-2026-46621 |
| Type | RCE |
| CVSS Score | 9.1 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-46621/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-2026-46621
# 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-2g95-6x5q-xjwj
- https://github.com/yamcs/yamcs/security/advisories/GHSA-2g95-6x5q-xjwj
Generated by PoC Generator on 2026-07-17T04:35:17.528367295
Frequently asked questions¶
What is CVE-2026-46621?¶
CVE-2026-46621 is a Critical (9.1) vulnerability: Yamcs is a mission control framework.. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-46621?¶
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-2026-46621?¶
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.