CVE-2026-26288: WebSocket Auth Bypass Vulnerability

CVE-2026-26288 Overview

CVE-2026-26288 is a critical authentication bypass vulnerability affecting OCPP (Open Charge Point Protocol) WebSocket endpoints in electric vehicle charging infrastructure. The vulnerability allows unauthenticated attackers to connect to WebSocket endpoints and impersonate legitimate charging stations, enabling unauthorized control of charging infrastructure and manipulation of backend data.

Critical Impact

Unauthenticated attackers can impersonate charging stations, issue OCPP commands, and corrupt charging network data without any authentication requirements.

Affected Products

• OCPP WebSocket endpoint implementations
• Electric vehicle charging station management systems
• Backend charging infrastructure control systems

Discovery Timeline

• 2026-03-06 - CVE-2026-26288 published to NVD
• 2026-03-10 - Last updated in NVD database

Technical Details for CVE-2026-26288

Vulnerability Analysis

This vulnerability stems from CWE-306: Missing Authentication for Critical Function. The OCPP WebSocket endpoints are designed to facilitate communication between electric vehicle charging stations and backend management systems. However, these endpoints lack proper authentication mechanisms, creating a significant security gap in the charging infrastructure.

An attacker who knows or can discover a charging station identifier can establish a WebSocket connection to the OCPP endpoint without providing any authentication credentials. Once connected, the attacker can send and receive OCPP commands as if they were a legitimate charger, effectively hijacking the communication channel between the charging station and the backend system.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any special privileges or user interaction. This makes the vulnerability particularly dangerous in environments where charging stations are deployed across distributed locations with public network exposure.

Root Cause

The root cause is the complete absence of authentication mechanisms on the OCPP WebSocket endpoints. The system accepts connections based solely on the charging station identifier without verifying the identity or authorization of the connecting party. This design flaw violates fundamental security principles for critical infrastructure communication protocols.

Attack Vector

The attack vector involves network-based exploitation where an attacker:

1. Identifies or enumerates valid charging station identifiers (which may follow predictable patterns or be discoverable through reconnaissance)
2. Establishes a WebSocket connection to the OCPP endpoint using the discovered identifier
3. Sends malicious OCPP commands to manipulate charging sessions, billing data, or infrastructure status
4. Receives sensitive operational data intended for the legitimate charging station

The exploitation does not require any authentication, user interaction, or special privileges, making it highly accessible to attackers with basic network access.

Detection Methods for CVE-2026-26288

Indicators of Compromise

• Multiple WebSocket connections from different IP addresses using the same charging station identifier
• Unusual OCPP command sequences that deviate from normal charging station behavior
• Geographic inconsistencies between charging station physical location and connection source IP
• Rapid connection attempts using sequential or enumerated station identifiers

Detection Strategies

• Implement network monitoring to detect WebSocket connections to OCPP endpoints from unexpected IP ranges
• Deploy behavioral analysis to identify anomalous OCPP command patterns indicative of impersonation
• Monitor for connection attempts using non-existent or decommissioned charging station identifiers
• Correlate charging station physical status with reported WebSocket activity to identify discrepancies

Monitoring Recommendations

• Enable comprehensive logging of all WebSocket connections including source IP, timestamps, and station identifiers
• Implement alerting for multiple simultaneous connections using the same charging station credentials
• Deploy network intrusion detection rules specific to OCPP protocol anomalies
• Conduct regular audits of charging station connectivity patterns to establish baselines

How to Mitigate CVE-2026-26288

Immediate Actions Required

• Implement network segmentation to restrict access to OCPP WebSocket endpoints from authorized networks only
• Deploy a VPN or private network connection between charging stations and backend systems
• Enable IP whitelisting for known charging station endpoints where feasible
• Review and audit all active WebSocket connections for unauthorized access

Patch Information

Consult the vendor-specific security advisories for patch availability. Technical details and remediation guidance are available through the CISA ICS Advisory and the GitHub CSAF JSON File.

Organizations should prioritize implementing authentication mechanisms on all OCPP WebSocket endpoints as the primary remediation strategy.

Workarounds

• Deploy network-level access controls such as firewalls and ACLs to restrict WebSocket endpoint access
• Implement TLS client certificate authentication as an additional authentication layer
• Use VPN tunnels to secure communication between charging stations and backend infrastructure
• Consider deploying a WebSocket proxy with authentication capabilities in front of vulnerable endpoints

# Example: Network segmentation using iptables to restrict OCPP WebSocket access
# Allow connections only from known charging station IP ranges
iptables -A INPUT -p tcp --dport 8080 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP