Preface: “Secure by Design” is a flawless theory when studying standards like IEC 62443 or automotive-specific ISO/SAE 21434, but in reality, original equipment manufacturers (OEMs) always compromise due to Bill of Materials (BOM) and production costs.

Background:

•               The Charging Station Side (EVSE): CVE-2026-7849 is strictly an OS Command Injection vulnerability within the Web management interface/REST API of the charging station controller (e.g., Phoenix Contact CHARX SEC-3000) [VDE-2026-008]. It cannot directly access or control the vehicle’s internal CAN bus.

•               The Vehicle Side (EV): The On-Board Charger (OBC) or Electric Vehicle Communication Controller (EVCC) acts as a strict Protocol Gateway between the Control Pilot (CP) line and the vehicle’s internal CAN bus. These two networks are physically and logically air-gapped from each other.

I presume that the design weaknesses of CVE-2026-7849 allow an attacker to compromise the EVSE. From there, they can attempt a secondary pivot attack to cause unknown impacts to the vehicle’s internal CAN Bus (see diagram point 7.1)

How my threat scenario becomes valid?
Stage 1: EVSE Compromise – Exploits CVE-2026-7849 to gain root access on the charging station.
Stage 2: Protocol Pivoting – Uses the station to send malformed digital packets (e.g., ISO 15118 over PLC) via J1772 CP line.
Stage 3: Firmware Exploit – Triggers a zero-day memory corruption / Buffer Overflow bug in the vehicle’s OBC firmware parser.
Stage 4: CAN Bus Injection – Achieves Remote Code Execution (RCE) on the OBC, using its legitimate node access to inject rogue frames onto the Dashboard’s CAN network.

Vulnerability details: Due to improper neutralization of special elements, an unauthenticated remote attacker is able to inject a command into the system configuration which is subsequently executed as root.

Reference: REST (Highest Risk)

• Why it easily triggers CWE-77: REST APIs fundamentally handle diverse, text-based data inputs (JSON, XML, URL parameters, form fields) that often directly influence backend operations.
• The Trigger Mechanism: Many embedded devices and IoT web panels use REST endpoints to accept configuration changes (e.g., setting an IP address, updating a hostname, or running a network ping). If the developer passes these text inputs directly into a backend operating system shell command (like system() or exec()) without strict input sanitization, an attacker can append command separators (like ;, &&, or |) to execute malicious code.

Official announcement: For details, please refer to link for details – https://www.tenable.com/cve/CVE-2026-7849