CVE-2026-21038: Samsung USB Driver Buffer Overflow Flaw

CVE-2026-21038 Overview

CVE-2026-21038 is an improper input validation vulnerability in the Samsung Android USB Driver for Windows prior to version 1.9.5.0. The driver fails to validate input properly, allowing a local attacker to access out-of-bounds memory. Exploitation requires local access to a Windows host that has the affected Samsung driver installed.

Successful exploitation can disclose adjacent kernel or driver memory contents and may destabilize the affected system. The flaw is categorized as an out-of-bounds read condition stemming from missing or insufficient bounds checks on input passed to the driver.

Critical Impact
A local attacker can trigger out-of-bounds memory access in the Samsung Android USB Driver for Windows, potentially leaking sensitive memory or causing system instability.

Affected Products

Samsung Android USB Driver for Windows prior to version 1.9.5.0
Windows hosts with the affected Samsung Android USB Driver installed
Samsung mobile device management workflows relying on the vulnerable driver

Discovery Timeline

2026-06-05 - CVE-2026-21038 published to the National Vulnerability Database (NVD)
2026-06-05 - Last updated in NVD database
June 2026 - Samsung Mobile Security Update referencing this issue published

Technical Details for CVE-2026-21038

Vulnerability Analysis

The vulnerability resides in the Samsung Android USB Driver for Windows, a kernel-mode component used to enable communication between Windows hosts and Samsung Android devices over USB. Versions prior to 1.9.5.0 do not properly validate input supplied to the driver. As a result, the driver reads or processes memory outside of intended buffer boundaries.

The attack vector is local. An attacker must already have the ability to interact with the driver on the target Windows machine, typically through I/O control requests sent from user mode. No user interaction is required once the attacker has local code execution context. The primary security impact is integrity loss in driver-managed memory and a high impact on availability, while confidentiality is rated as none in the published CVSS metrics.

Root Cause

The root cause is improper input validation. The driver accepts attacker-controlled values, likely indices, sizes, or offsets, and uses them to access memory regions without verifying that the resulting access falls within allocated buffers. This produces an out-of-bounds memory access condition in a kernel driver.

Attack Vector

A local user on a Windows system with the vulnerable driver installed crafts malformed input and submits it to the driver through standard I/O control interfaces. The driver dereferences the input without sufficient bounds checking, triggering out-of-bounds memory access. The condition can lead to driver or system instability and may reveal adjacent memory contents.

No verified public proof-of-concept code is available. Refer to the Samsung Mobile Security Update for vendor technical details.

Detection Methods for CVE-2026-21038

Indicators of Compromise

Unexpected crashes, bug checks, or stop errors on Windows hosts referencing the Samsung Android USB driver module
Driver-related kernel exceptions logged in the Windows Event Log shortly after USB-related activity
Presence of Samsung Android USB Driver versions prior to 1.9.5.0 on managed Windows endpoints

Detection Strategies

Inventory installed driver versions across Windows endpoints and flag any Samsung Android USB Driver below 1.9.5.0
Monitor for abnormal user-mode processes issuing I/O control requests to the Samsung USB driver device object
Correlate Windows Error Reporting and kernel crash telemetry with the loaded Samsung USB driver image

Monitoring Recommendations

Forward kernel crash dumps and driver fault events to a centralized logging or SIEM platform for analysis
Alert on local privilege escalation patterns and anomalous handle opens against Samsung USB driver device paths
Track software inventory changes to detect installation of outdated Samsung Android USB Driver packages

How to Mitigate CVE-2026-21038

Immediate Actions Required

Update the Samsung Android USB Driver for Windows to version 1.9.5.0 or later on all affected hosts
Restrict local access to systems that require the Samsung Android USB Driver, particularly multi-user workstations
Remove the Samsung Android USB Driver from Windows endpoints that do not need to connect to Samsung Android devices

Patch Information

Samsung addresses this issue in Samsung Android USB Driver for Windows version 1.9.5.0. Apply the update referenced in the Samsung Mobile Security Update advisory for June 2026.

Workarounds

Uninstall the Samsung Android USB Driver on hosts where Samsung device connectivity is not required
Limit interactive logon rights on systems running the affected driver to trusted administrative users
Disable USB device installation policies for unmanaged Samsung Android devices through Group Policy where feasible

bash

# Configuration example: query installed Samsung Android USB Driver version on Windows
powershell -Command "Get-WmiObject Win32_PnPSignedDriver | Where-Object { $_.DeviceName -like '*Samsung*USB*' } | Select-Object DeviceName, DriverVersion"