CVE-2026-44807: Windows DWM Privilege Escalation Flaw

CVE-2026-44807 Overview

CVE-2026-44807 is a use-after-free vulnerability in the Windows Desktop Window Manager (DWM) Core Library. An authorized local attacker can exploit the flaw to elevate privileges on an affected Windows system. The weakness is classified under [CWE-416] (Use After Free) and carries a CVSS 3.1 base score of 7.8.

Microsoft published the advisory on 2026-06-09 through the Microsoft Security Response Center. Successful exploitation gives the attacker access at a higher integrity level, allowing further compromise of the host.

Critical Impact
A local, authenticated attacker can corrupt freed memory inside dwmcore.dll to achieve privilege escalation with high impact on confidentiality, integrity, and availability.

Affected Products

Microsoft Windows (DWM Core Library component)
Refer to the Microsoft Security Update CVE-2026-44807 advisory for the full list of affected builds
Specific KB article and version mappings are published in the MSRC update guide

Discovery Timeline

2026-06-09 - CVE CVE-2026-44807 published to NVD
2026-06-09 - Last updated in NVD database

Technical Details for CVE-2026-44807

Vulnerability Analysis

The Desktop Window Manager (DWM) is the Windows compositor responsible for rendering the graphical desktop, window animations, and visual effects. The DWM Core Library runs with elevated privileges and processes graphics primitives on behalf of user-mode applications. A use-after-free condition inside this component lets an attacker reference memory that has already been released back to the allocator.

When an authorized local user triggers the vulnerable code path, the library frees an internal object but retains a stale pointer. Subsequent operations dereference that pointer, allowing the attacker to influence the contents of the freed allocation. Controlling the reused memory enables hijacking of object virtual tables or function pointers in the DWM process, which executes with SYSTEM privileges.

The outcome is a local elevation of privilege, giving the attacker high impact on confidentiality, integrity, and availability of the host.

Root Cause

The root cause is improper object lifetime management inside the DWM Core Library. The component releases a heap object while another code path still holds a reference to it. The next access to that reference operates on attacker-influenced memory, satisfying the conditions for [CWE-416] exploitation.

Attack Vector

The attack vector is local. An attacker must already have the ability to execute code on the target system as an authenticated, low-privileged user. From that foothold, the attacker invokes graphics APIs or sends crafted compositor messages that drive the vulnerable allocation and free sequence inside DWM. No user interaction is required to complete the privilege escalation once code execution is achieved.

No public proof-of-concept exploit, exploit database entry, or in-the-wild exploitation has been reported as of publication. The vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog.

No verified exploitation code is available. See the Microsoft Security Update CVE-2026-44807 advisory for technical details published by the vendor.

Detection Methods for CVE-2026-44807

Indicators of Compromise

Unexpected crashes or restarts of the dwm.exe process, particularly with access-violation exception codes, may indicate exploitation attempts against the DWM Core Library.
New child processes spawned by dwm.exe or winlogon.exe running with SYSTEM integrity following user-launched graphical applications.
Creation or modification of services, scheduled tasks, or persistence artifacts shortly after anomalous DWM process behavior on a host.

Detection Strategies

Monitor Windows Error Reporting (WER) and crash dumps for repeated faults in dwmcore.dll and correlate with the originating user session.
Hunt for low-privileged user accounts performing actions that require elevated rights within minutes of suspicious DWM activity.
Apply behavioral identification rules that flag privilege transitions from medium to high or SYSTEM integrity without a legitimate elevation path.

Monitoring Recommendations

Enable Sysmon process creation (Event ID 1) and process access (Event ID 10) logging, focusing on dwm.exe as both source and target.
Ingest Windows Security and Application logs into a centralized SIEM and alert on unexpected token elevation events (Event ID 4672) tied to recently authenticated standard users.
Track installed cumulative update levels across the fleet to identify hosts that remain unpatched against CVE-2026-44807.

How to Mitigate CVE-2026-44807

Immediate Actions Required

Apply the Microsoft security update referenced in the MSRC advisory for CVE-2026-44807 to all affected Windows systems.
Prioritize patch deployment on multi-user systems such as Remote Desktop Session Hosts, Virtual Desktop Infrastructure, and shared workstations where local users are most likely to chain this flaw.
Restrict local logon and interactive session rights to trusted accounts until patching is verified across the environment.

Patch Information

Microsoft has released a security update addressing CVE-2026-44807. Consult the Microsoft Security Update CVE-2026-44807 entry for the specific KB numbers, build versions, and download links applicable to each supported Windows release.

Workarounds

No vendor-supplied workaround eliminates the vulnerability. Patching is the only complete remediation.
Reduce exposure by enforcing the principle of least privilege and removing unnecessary local accounts from systems handling sensitive workloads.
Apply application control policies such as Windows Defender Application Control or AppLocker to limit which binaries unprivileged users can execute on the host.

bash

# Verify the installed update level on a Windows host
wmic qfe list brief /format:table

# PowerShell equivalent listing recent security updates
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 20