ocpp_j.c contains a stack buffer overflow in…¶

Key facts

CVE-2026-13214 is a Critical (9.8) vulnerability: The OCPP 1.6 client in subsys/net/lib/ocpp/ocpp_j.c contains a stack buffer overflow in…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-13214
Severity	Critical (9.8)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-13214/

Details¶

English | 한국어

Description¶

The OCPP 1.6 client in subsys/net/lib/ocpp/ocpp_j.c contains a stack buffer overflow in parse_getconfig_msg(). When handling a GetConfiguration request from the central system, the handler copied the attacker-controlled JSON "key" string into the caller's fixed 50-byte stack buffer (skey[CISTR50], declared in subsys/net/lib/ocpp/ocpp.c) using an unbounded strcpy(). The parsed key value points directly into the receive buffer, so its length is bounded only by the message size (CONFIG_OCPP_RECV_BUFFER_SIZE, default 2048).

The GetConfiguration message is delivered over the WebSocket connection that the charge point opens to its configured central system. The reader thread ocpp_wsreader() reads the message into ui->recv_buf and dispatches it to parse_getconfig_msg() via the PDU function table. An attacker who controls the central system endpoint, or a man-in-the-middle on an unencrypted connection, can send a GetConfiguration request whose "key" field exceeds 50 bytes and overflow the reader thread's stack with attacker-chosen bytes.

The consequence is a remotely triggerable stack smash on the OCPP reader thread: at minimum a denial of service, and plausibly remote code execution depending on build-time hardening such as stack canaries and MPU configuration. The fix replaces the strcpy() with a bounded strncpy(key, payload.key[0], CISTR50 - 1) followed by explicit NUL termination, matching the bounded copies already used by the sibling handlers.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-13214
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-2026-13214/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-2026-13214

# 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/zephyrproject-rtos/zephyr/commit/afbf880b04188ae53451a0ade4ac62b654fdff34
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fqhf-6v24-4px2

Generated by PoC Generator on 2026-08-25T14:55:48.351210933

Frequently asked questions¶

What is CVE-2026-13214?¶

CVE-2026-13214 is a Critical (9.8) vulnerability: The OCPP 1.6 client in subsys/net/lib/ocpp/ocpp_j.c contains a stack buffer overflow in…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-13214?¶

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-2026-13214?¶

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.