CVE-2026-25114: Cloudcharge.se WebSocket DOS Vulnerability

CVE-2026-25114 Overview

CVE-2026-25114 is an Improper Restriction of Excessive Authentication Attempts vulnerability (CWE-307) affecting the CloudCharge cloudcharge.se platform. The WebSocket Application Programming Interface lacks restrictions on the number of authentication requests, creating a significant security risk for electric vehicle charging infrastructure.

This absence of rate limiting may allow an attacker to conduct denial-of-service attacks by suppressing or mis-routing legitimate charger telemetry, or conduct brute-force attacks to gain unauthorized access to charging station management systems.

Critical Impact

Attackers can exploit the missing rate limiting to perform brute-force authentication attacks or cause denial-of-service conditions affecting EV charging infrastructure telemetry and operations.

Affected Products

• CloudCharge cloudcharge.se (all versions)

Discovery Timeline

• 2026-02-27 - CVE-2026-25114 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-25114

Vulnerability Analysis

The vulnerability resides in the WebSocket API endpoint responsible for handling authentication requests within the CloudCharge platform. The API implementation fails to enforce any form of rate limiting or throttling mechanism on incoming authentication attempts. This design flaw allows attackers to submit an unlimited number of authentication requests without triggering protective countermeasures.

In the context of EV charging infrastructure, this vulnerability is particularly concerning. The CloudCharge platform manages telemetry data from charging stations, including usage data, billing information, and operational status. Successful exploitation could allow attackers to compromise charging station management, potentially disrupting electric vehicle charging services at scale.

Root Cause

The root cause is the absence of authentication rate limiting controls in the WebSocket API implementation. The system does not implement:

• Request throttling per source IP address
• Account lockout mechanisms after failed attempts
• Progressive delays between authentication attempts
• CAPTCHA or challenge-response mechanisms

This allows unlimited authentication attempts to be processed without restriction, violating security best practices for authentication endpoints.

Attack Vector

The attack is network-based and requires no prior authentication or user interaction. An attacker can exploit this vulnerability remotely by:

1. Establishing a WebSocket connection to the CloudCharge API endpoint
2. Sending rapid, automated authentication requests with varying credentials
3. For brute-force attacks: Attempting common or leaked passwords until valid credentials are discovered
4. For DoS attacks: Flooding the authentication endpoint to exhaust server resources or disrupt legitimate telemetry communications

The vulnerability is particularly dangerous because the WebSocket protocol maintains persistent connections, making sustained attacks more efficient. Attackers can target individual charging stations by suppressing or manipulating telemetry data, potentially causing service disruptions or enabling further attacks on the charging infrastructure.

Detection Methods for CVE-2026-25114

Indicators of Compromise

• Abnormally high volume of WebSocket authentication requests from single IP addresses or IP ranges
• Rapid succession of failed authentication attempts against the CloudCharge API
• Unusual patterns in WebSocket connection establishment and termination
• Gaps or anomalies in charger telemetry data streams that may indicate suppression
• Authentication logs showing systematic credential enumeration patterns

Detection Strategies

• Implement network monitoring to detect high-frequency WebSocket connections to CloudCharge endpoints
• Configure SIEM rules to alert on authentication failure rate thresholds exceeding normal baselines
• Monitor for brute-force attack patterns using failed authentication attempt correlation
• Deploy intrusion detection signatures for WebSocket-based credential stuffing attacks
• Analyze traffic patterns for automated tool signatures commonly used in authentication attacks

Monitoring Recommendations

• Establish baseline metrics for normal authentication request volumes and monitor for deviations
• Implement real-time alerting for sustained authentication failures from individual source IPs
• Monitor charging station telemetry data integrity and availability for signs of disruption
• Review CloudCharge API access logs regularly for suspicious authentication patterns
• Configure dashboards to visualize WebSocket connection metrics and authentication success/failure ratios

How to Mitigate CVE-2026-25114

Immediate Actions Required

• Contact CloudCharge support to inquire about available patches or mitigations via their support portal
• Implement network-level rate limiting on WebSocket API endpoints using web application firewalls or reverse proxies
• Restrict API access to known IP addresses or VPN connections where operationally feasible
• Enable enhanced logging and monitoring for authentication events
• Review the CISA ICS Advisory for additional guidance

Patch Information

At the time of publication, specific vendor patch information is not available in the CVE data. Organizations should:

• Monitor CloudCharge vendor communications for security updates
• Review the GitHub CSAF file for structured vulnerability information
• Contact CloudCharge support directly to determine remediation options and timelines
• Subscribe to CISA ICS advisories for updates on industrial control system vulnerabilities

Workarounds

• Deploy a reverse proxy with rate limiting capabilities in front of the CloudCharge WebSocket API
• Implement IP-based access control lists to restrict API access to authorized networks only
• Configure network firewalls to detect and block high-frequency connection attempts
• Consider implementing additional authentication factors where supported by the platform
• Segment the charging infrastructure network to limit exposure of the vulnerable API endpoint

# Example nginx rate limiting configuration for WebSocket endpoints
# Add to nginx configuration to limit authentication requests

limit_req_zone $binary_remote_addr zone=ws_auth:10m rate=10r/s;

location /ws/auth {
    limit_req zone=ws_auth burst=20 nodelay;
    limit_req_status 429;
    proxy_pass http://cloudcharge_backend;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
}