CVE-2026-49804: Windows 10 Privilege Escalation Vulnerability

CVE-2026-49804 Overview

CVE-2026-49804 is a heap-based buffer overflow [CWE-122] in the Windows USB Video Class (UVC) driver. An unauthorized attacker with physical access to a target system can exploit the flaw to elevate privileges. Exploitation requires user interaction, such as connecting a malicious USB video device to the machine.

Microsoft addressed the issue across a wide range of supported Windows client and server releases, including Windows 10, Windows 11, and Windows Server editions from 2012 through 2025. The vulnerability is tracked under Microsoft advisory CVE-2026-49804.

Critical Impact
Successful exploitation grants an attacker with physical access elevated privileges on the target host, enabling full compromise of confidentiality, integrity, and availability.

Affected Products

Microsoft Windows 10 (1607, 1809, 21H2, 22H2) on x86, x64, and ARM64
Microsoft Windows 11 (24H2, 25H2) on x64 and ARM64
Microsoft Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025

Discovery Timeline

2026-07-14 - CVE-2026-49804 published to NVD
2026-07-16 - Last updated in NVD database

Technical Details for CVE-2026-49804

Vulnerability Analysis

The flaw resides in the Windows USB Video Driver, which parses descriptors and streaming data from attached USB video devices. A heap-based buffer overflow occurs when the driver processes attacker-controlled input from a malicious USB device. Writing past the allocated heap buffer allows corruption of adjacent kernel heap structures.

Because the USB Video Driver runs in kernel mode, memory corruption directly translates to a privilege escalation primitive. Attackers can leverage overwritten function pointers or object headers to redirect execution or manipulate access tokens, resulting in SYSTEM-level access.

Root Cause

The root cause is insufficient bounds validation on descriptor or frame data received from a USB device. The driver allocates a fixed-size heap buffer based on assumed or partially validated length fields, then copies attacker-supplied data without enforcing the allocation size, satisfying the pattern described by [CWE-122].

Attack Vector

Exploitation requires physical access and user interaction. The attacker connects a crafted USB device that emulates a UVC-compliant camera but returns malformed descriptors or streaming payloads. When Windows enumerates the device and the driver parses the data, the overflow triggers in kernel context.

This vector is relevant to unattended workstations, kiosks, conference room systems, and endpoints in shared environments where a brief window of physical access is achievable. No prior authentication on the target is required.

No public proof-of-concept or in-the-wild exploitation has been reported for CVE-2026-49804, and it is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-49804

Indicators of Compromise

Unexpected USB video device enumeration events in Microsoft-Windows-USB-USBHUB3 or Microsoft-Windows-Kernel-PnP logs on systems where such devices are not typically used.
Kernel-mode crashes or bug checks referencing the USB Video Class driver (usbvideo.sys) shortly after a device insertion.
Creation of new privileged processes or services immediately following a USB device connection event.

Detection Strategies

Monitor Windows event logs for PnP device installation events (Event IDs 20001, 20003) correlated with subsequent process creations running as SYSTEM.
Alert on kernel crashes or WER reports naming usbvideo.sys as the faulting module.
Use EDR telemetry to flag anomalous parent-child process relationships originating from kernel-adjacent services after USB insertion.

Monitoring Recommendations

Deploy USB device control policies that log every insertion and removal, including vendor and product identifiers.
Correlate physical access events (badge readers, camera feeds) with USB enumeration telemetry on high-value endpoints.
Track patch compliance for the affected Windows builds using vulnerability management tooling and Microsoft Update reports.

How to Mitigate CVE-2026-49804

Immediate Actions Required

Apply the Microsoft security update referenced in the Microsoft Security Update Guide for CVE-2026-49804 to all affected Windows client and server systems.
Prioritize patching for endpoints in publicly accessible or shared physical locations, including kiosks, conference rooms, and lobbies.
Verify that automatic driver installation policies do not silently load third-party USB video drivers that could bypass the fix.

Patch Information

Microsoft has released cumulative security updates addressing CVE-2026-49804 for all supported Windows 10, Windows 11, and Windows Server versions listed in the advisory. Consult the Microsoft Security Update Guide for the specific KB article corresponding to each affected build.

Workarounds

Enforce USB device control through Group Policy or Microsoft Intune to block unauthorized USB video class devices on managed endpoints.
Disable the USB Video Class driver on systems that do not require camera functionality by restricting device class GUID {6BDD1FC6-810F-11D0-BEC7-08002BE2092F} via device installation restrictions.
Enforce physical security controls including port blockers, locked enclosures, and access monitoring for endpoints in exposed locations.

bash

# Configuration example: Block USB Video Class device installation via Group Policy
# Computer Configuration > Administrative Templates > System > Device Installation > Device Installation Restrictions
# Setting: Prevent installation of devices using drivers that match these device setup classes
# Add class GUID: {6BDD1FC6-810F-11D0-BEC7-08002BE2092F}

# Verify via PowerShell:
Get-PnpDevice -Class Image | Where-Object { $_.Status -eq 'OK' }