CVE-2026-15476: QILING Disk Master Privilege Escalation

CVE-2026-15476 Overview

CVE-2026-15476 is an improper access control vulnerability in QILING Disk Master 6.0.0.0. The flaw resides in an unspecified function within the diskbckp.sys kernel driver, a component of the disk backup product. A local, authenticated attacker can interact with the driver's exposed interface to abuse insufficient permission checks. The issue is tracked as CWE-266: Incorrect Privilege Assignment. Public disclosure of exploitation details has occurred through VulDB Vulnerability #377781, increasing the likelihood of opportunistic abuse against unpatched hosts.

Critical Impact
A local user can leverage the vulnerable kernel driver to obtain elevated privileges on affected Windows systems running QILING Disk Master 6.0.0.0.

Affected Products

QILING Disk Master 6.0.0.0
Component: Kernel Driver diskbckp.sys
Platform: Microsoft Windows (kernel-mode driver)

Discovery Timeline

2026-07-12 - CVE-2026-15476 published to NVD
2026-07-13 - Last updated in NVD database

Technical Details for CVE-2026-15476

Vulnerability Analysis

The vulnerability exists in the diskbckp.sys kernel-mode driver shipped with QILING Disk Master 6.0.0.0. The driver exposes functionality to user-mode callers without enforcing adequate access controls on privileged operations. A local user with standard privileges can open a handle to the driver's device object and issue IOCTLs that should be restricted to administrative contexts. Analysis published by Winslow's CVE Collection characterizes the flaw as a local privilege escalation path through the driver interface.

Root Cause

The root cause is improper privilege assignment [CWE-266] in the driver's security descriptor or IOCTL dispatch logic. The driver does not verify that the calling process holds the required privileges before executing sensitive kernel-mode operations. Disk backup drivers typically expose raw read and write primitives against block devices, and exposing these to unprivileged callers grants effective SYSTEM-level control over on-disk data.

Attack Vector

Exploitation requires local access and a low-privileged account on the target Windows system. The attacker opens the driver's device object using CreateFileW against the driver's exposed device name, then issues DeviceIoControl calls to invoke the unprotected functionality. Because the operation runs in kernel context, an attacker can manipulate disk sectors, overwrite privileged files, or stage further code execution as SYSTEM. Remote exploitation is not possible; the attacker must already be authenticated on the host.

No verified proof-of-concept code is republished here. Technical write-ups are available via the VulDB entry and the linked community analysis.

Detection Methods for CVE-2026-15476

Indicators of Compromise

Presence of diskbckp.sys at version 6.0.0.0 loaded in the kernel on hosts that do not require QILING Disk Master.
Unexpected CreateFile handles to the QILING driver device object opened by non-administrative processes.
New SYSTEM-level processes spawned from user sessions shortly after interaction with the driver.

Detection Strategies

Inventory endpoints for the vulnerable diskbckp.sys driver file and confirm the file version equals 6.0.0.0.
Hunt for DeviceIoControl activity against the QILING driver from non-elevated processes using EDR telemetry.
Correlate driver load events (Windows Event ID 6 in Sysmon) with subsequent token elevation or SYSTEM process creation.

Monitoring Recommendations

Enable kernel driver load auditing and forward events to a central SIEM for review.
Alert on installation of diskbckp.sys outside authorized software deployment channels.
Track file integrity of driver binaries in %SystemRoot%\System32\drivers\ to detect tampering or downgrade attempts.

How to Mitigate CVE-2026-15476

Immediate Actions Required

Identify all hosts running QILING Disk Master 6.0.0.0 and prioritize them for remediation.
Restrict local logon rights on affected systems to reduce the pool of accounts able to invoke the driver.
Remove or disable QILING Disk Master where the backup functionality is not business-critical.

Patch Information

The vendor advises upgrading the affected component. Users should obtain the latest release from the vendor and verify that the shipped diskbckp.sys is a version higher than 6.0.0.0. Reference the vendor download portal via the iDiskHome distribution page and confirm authenticity before deployment.

Workarounds

Uninstall QILING Disk Master 6.0.0.0 on systems where an updated build is not yet available.
Apply Windows driver blocklist policies to prevent loading of the vulnerable diskbckp.sys version.
Enforce least-privilege access controls so only trusted administrators can log on interactively to affected hosts.

bash

# Query for the vulnerable driver on Windows endpoints (PowerShell)
Get-ChildItem -Path C:\Windows\System32\drivers\diskbckp.sys -ErrorAction SilentlyContinue |
  Select-Object FullName, @{Name='Version';Expression={$_.VersionInfo.FileVersion}}