CVE-2026-44102: OCPP Backend Auth Bypass Vulnerability

CVE-2026-44102 Overview

CVE-2026-44102 is a race condition vulnerability affecting devices implementing an Open Charge Point Protocol (OCPP) backend. An unauthenticated remote attacker can trigger a firmware update download by supplying an invalid firmware file to the OCPP backend. The invalid file remains accessible on the device for a short window before cleanup completes, due to improper locking during the deletion routine. The issue is tracked under [CWE-362] (Concurrent Execution using Shared Resource with Improper Synchronization) and is documented in the CERT-VDE Security Advisory.

Critical Impact
An unauthenticated network attacker can cause invalid firmware files to be staged on the target device and briefly exposed before cleanup, creating a limited-integrity impact on the OCPP-enabled system.

Affected Products

OCPP-compliant charging infrastructure referenced in CERT-VDE advisory VDE-2026-008
Specific vendor and product identifiers were not published in the NVD entry
Refer to the CERT-VDE advisory for the authoritative affected product list

Discovery Timeline

2026-07-30 - CVE-2026-44102 published to NVD
2026-07-30 - Last updated in NVD database

Technical Details for CVE-2026-44102

Vulnerability Analysis

The vulnerability resides in the firmware update handling logic exposed through the Open Charge Point Protocol (OCPP) backend. OCPP allows a management system to instruct charging stations to fetch firmware images from a remote URL. In the affected implementation, the device accepts the download request without authentication and retrieves the file to local storage. When the file fails validation as a legitimate firmware image, the cleanup path attempts to remove it. Improper locking during this cleanup allows the file to remain accessible on the device for a short interval before deletion completes.

This constitutes a Time-of-Check to Time-of-Use (TOCTOU) style race condition, categorized under [CWE-362]. The lack of authentication on the trigger amplifies the exposure by allowing any remote party with network reachability to initiate the download.

Root Cause

The root cause is missing or insufficient synchronization around the file cleanup routine after firmware validation failure. The download, validation, and deletion operations do not execute as an atomic sequence. During the gap between validation failure and file removal, the file resides in a path accessible to other processes or protocol handlers on the device.

Attack Vector

The attack is executed over the network without authentication or user interaction. An attacker interacts with the OCPP backend and requests a firmware update pointing to an attacker-controlled URL hosting an invalid firmware image. The device downloads the file, fails to validate it, and enters the flawed cleanup routine. During the brief window, the staged file is accessible on the device. The CVSS v4.0 vector indicates an integrity-only impact on the vulnerable system (VI:L), with no direct confidentiality or availability consequence.

No public proof-of-concept exploit or exploit database entry is currently listed for this CVE. Technical details are described narratively in the CERT-VDE Security Advisory.

Detection Methods for CVE-2026-44102

Indicators of Compromise

Unexpected firmware update requests received by an OCPP-connected charging station from unauthorized backends or endpoints
Presence of transient files in the firmware staging directory that do not correspond to a legitimate update campaign
OCPP UpdateFirmware calls originating from IP addresses outside the approved central system

Detection Strategies

Inspect OCPP backend logs for UpdateFirmware messages that reference external or unrecognized download URLs
Monitor charging station file systems for creation of firmware artifacts outside scheduled maintenance windows
Correlate network traffic to charging stations against an allow-list of legitimate central system management endpoints

Monitoring Recommendations

Enable verbose logging on the OCPP backend to capture the source, timing, and URL parameters of every firmware update request
Alert on repeated firmware download failures on any single station, which may indicate exploitation attempts against the cleanup race
Forward charging infrastructure telemetry to a central SIEM or data lake for cross-fleet analysis and anomaly identification

How to Mitigate CVE-2026-44102

Immediate Actions Required

Review the CERT-VDE Security Advisory to identify affected firmware versions in your fleet
Restrict network reachability of the OCPP backend to trusted central system endpoints only
Disable or gate remote firmware update functionality until a vendor patch is applied

Patch Information

Refer to the CERT-VDE Security Advisory VDE-2026-008 for vendor-issued firmware updates that address the improper locking in the cleanup routine. No fixed version identifiers were published in the NVD record at the time of publication.

Workarounds

Deploy OCPP traffic through an authenticated, TLS-secured tunnel between the charging station and the central system
Apply network segmentation and firewall rules to block inbound connections to the OCPP backend from untrusted networks
Enforce mutual TLS (mTLS) or equivalent authentication at the OCPP transport layer where supported
Audit and remove any unused firmware staging directories or lingering files during scheduled maintenance

bash

# Example: restrict OCPP backend access to a known central system
iptables -A INPUT -p tcp --dport 8080 -s <central-system-ip> -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP