CVE-2026-25851: Chargemap Auth Bypass Vulnerability

CVE-2026-25851 Overview

CVE-2026-25851 is a critical authentication bypass vulnerability affecting Chargemap's WebSocket endpoints used for the Open Charge Point Protocol (OCPP). The WebSocket endpoints lack proper authentication mechanisms, enabling attackers to perform unauthorized station impersonation and manipulate data sent to the backend. An unauthenticated attacker can connect to the OCPP WebSocket endpoint using a known or discovered charging station identifier, then issue or receive OCPP commands as a legitimate charger.

Critical Impact
This vulnerability allows complete unauthorized control of electric vehicle charging infrastructure, enabling privilege escalation, data manipulation, and potential disruption of charging network operations without any authentication.

Affected Products

Chargemap chargemap.com (all versions)

Discovery Timeline

2026-02-27 - CVE-2026-25851 published to NVD
2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-25851

Vulnerability Analysis

This vulnerability stems from the absence of authentication controls on WebSocket endpoints that handle OCPP communications between charging stations and the backend management system. OCPP (Open Charge Point Protocol) is an application protocol for communication between Electric Vehicle charging stations and a central management system. The vulnerability is classified under CWE-306 (Missing Authentication for Critical Function).

The attack can be executed remotely over the network without requiring any prior authentication or user interaction. Once connected, an attacker gains the ability to issue commands as if they were a legitimate charging station, receive sensitive operational data, and potentially manipulate charging sessions and billing information.

Root Cause

The root cause of this vulnerability is the complete absence of authentication mechanisms on the OCPP WebSocket endpoint. The system accepts connections from any client that knows or can discover a valid charging station identifier, without verifying the identity or authorization of the connecting party. This design flaw allows attackers to impersonate any charging station in the network.

Attack Vector

The attack is network-based and requires no authentication, privileges, or user interaction. An attacker can exploit this vulnerability by following these steps:

Discovery Phase: Identify or enumerate valid charging station identifiers through reconnaissance or information gathering
Connection Establishment: Establish a WebSocket connection to the OCPP endpoint using a discovered station identifier
Impersonation: Send and receive OCPP commands as the impersonated charging station
Exploitation: Manipulate charging sessions, corrupt backend data, or disrupt charging infrastructure operations

The vulnerability allows for privilege escalation within the charging network, unauthorized control of charging infrastructure, and corruption of charging network data reported to the backend system.

Detection Methods for CVE-2026-25851

Indicators of Compromise

Unexpected WebSocket connections from unrecognized IP addresses to OCPP endpoints
Multiple connection attempts using various charging station identifiers from the same source
Anomalous OCPP command patterns or commands issued outside normal operational hours
Duplicate station identifiers connecting simultaneously from different network locations

Detection Strategies

Implement network monitoring to track all WebSocket connections to OCPP endpoints
Deploy anomaly detection to identify unusual command patterns or connection behaviors
Monitor for connections from IP ranges outside expected charging station deployments
Correlate physical charging station status with backend communication logs to detect impersonation

Monitoring Recommendations

Enable comprehensive logging of all OCPP WebSocket connections including source IP, timestamps, and station identifiers
Configure alerts for simultaneous connections using the same station identifier from different sources
Monitor for rapid connection/disconnection patterns that may indicate enumeration attempts
Review OCPP command logs for unauthorized or unexpected operations

How to Mitigate CVE-2026-25851

Immediate Actions Required

Contact Chargemap support through their Support Page for vendor-specific guidance
Implement network-level access controls to restrict OCPP endpoint access to known charging station IP ranges
Deploy a Web Application Firewall (WAF) or API gateway to add authentication layers
Review the CISA ICS Advisory #ICSA-26-057-05 for additional guidance

Patch Information

No vendor patch information is currently available in the CVE data. Organizations should contact Chargemap directly through their support channels for remediation guidance. Additional technical details can be found in the GitHub CSAF JSON File published by CISA.

Workarounds

Implement TLS client certificate authentication for all WebSocket connections to OCPP endpoints
Deploy network segmentation to isolate charging infrastructure from untrusted networks
Use VPN tunnels or private network connections between charging stations and backend systems
Implement IP allowlisting to restrict OCPP endpoint access to known station addresses
Consider deploying an authentication proxy layer in front of the OCPP WebSocket endpoints

bash

# Example network segmentation configuration (iptables)
# Restrict OCPP WebSocket access to known charging station IP ranges
iptables -A INPUT -p tcp --dport 443 -s 10.20.30.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP