CVE-2026-12562 — The RCU II+ and Multiload II+ are vulnerable to an unauthenticated¶
Key facts
CVE-2026-12562 is a High (8.8) vulnerability: The RCU II+ and Multiload II+ are vulnerable to an unauthenticated. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-12562 |
| Severity | High (8.8) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-12562/ |
Details¶
English | 한국어
Description¶
The RCU II+ and Multiload II+ are vulnerable to an unauthenticated service that exposes a debug interface granting full root-level access to the embedded system. This vulnerability stems from a network-accessible port running a Target Communications Framework (TCF) service that does not require any authentication, allowing an attacker to directly interact with the Linux environment that powers the device. Once connected, an attacker can freely view and modify the filesystem, manipulate running processes, and control network interfaces, enabling deep alteration of system behavior.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-12562 |
| CVSS Score | 8.8 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-12562/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-2026-12562
# 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/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-03.json
- https://s3.amazonaws.com/docs.toptech.com/index.html#downloads/Firmware/RCUII+_MLII+_SMPII+/
- https://s3.amazonaws.com/docs.toptech.com/nonpublic/2025%2012%2001%20RCU%20IIPlus%20MultiLoad%20IIPlus%20Vulnerability%20Notice.pdf
- https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.gz
- https://s3.amazonaws.com/docs.toptech.com/nonpublic/rcuiip_mliip_vrt.zip
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-03
Generated by PoC Generator on 2026-08-01T23:06:33.435609248
Frequently asked questions¶
What is CVE-2026-12562?¶
CVE-2026-12562 is a High (8.8) vulnerability: The RCU II+ and Multiload II+ are vulnerable to an unauthenticated. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-12562?¶
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-2026-12562?¶
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.