CVE-2026-44814: Windows DWM Information Disclosure Flaw

CVE-2026-44814 Overview

CVE-2026-44814 is an out-of-bounds read vulnerability in the Windows Desktop Window Manager (DWM) Core Library. An authorized local attacker can exploit the flaw to read memory contents outside the intended buffer boundary, leading to information disclosure. The weakness is classified under [CWE-122] (Heap-based Buffer Overflow category, applied here to bounds-violating read operations).

The vulnerability requires local access and low privileges, with no user interaction. Successful exploitation impacts confidentiality but does not affect integrity or availability. Microsoft published the advisory through the Microsoft Security Response Center.

Critical Impact
An authenticated local attacker can disclose sensitive memory contents from the Windows DWM Core Library, potentially exposing data useful for further privilege escalation or sandbox escape chains.

Affected Products

Microsoft Windows (versions specified in the Microsoft advisory)
Windows DWM Core Library component
See the Microsoft CVE-2026-44814 Advisory for the complete list of affected builds

Discovery Timeline

2026-06-09 - CVE-2026-44814 published to the National Vulnerability Database
2026-06-09 - Last updated in NVD database

Technical Details for CVE-2026-44814

Vulnerability Analysis

The Desktop Window Manager (DWM) Core Library handles composition, rendering, and graphical effects for the Windows desktop. CVE-2026-44814 stems from an out-of-bounds read condition within this component. When the affected code path processes a graphics or composition request, it reads memory beyond the boundaries of an allocated buffer.

The disclosed memory may contain pointers, handles, or process data that supports later attack stages. The flaw does not permit memory modification, so integrity and availability are unaffected. However, leaked memory layout information frequently aids bypassing protections such as Address Space Layout Randomization (ASLR).

With a low Exploit Prediction Scoring System (EPSS) probability, immediate mass exploitation is unlikely, but local privilege escalation chains commonly bundle such information disclosure primitives.

Root Cause

The root cause is improper validation of buffer boundaries when DWM Core Library code accesses heap-resident data structures. The function reads adjacent memory because length or index checks are missing or incorrectly applied before the read operation. This matches the [CWE-122] classification for heap-based memory errors.

Attack Vector

Exploitation requires local code execution on the target system with at least low-privileged user rights. No user interaction is needed. The attacker invokes DWM functionality from a local process, triggers the vulnerable code path, and captures the leaked memory contents. The vulnerable read happens within the DWM process boundary, so the attacker must coerce DWM into reading the unintended memory region and surface that data back to the attacker-controlled process.

No public proof-of-concept exploit, CISA KEV listing, or Exploit-DB entry exists for this CVE at the time of publication.

Detection Methods for CVE-2026-44814

Indicators of Compromise

Unexpected crashes or exception logs referencing dwmcore.dll in Windows Error Reporting (WER) data
Local processes making unusual sequences of graphics or composition API calls under low-privileged user contexts
Memory access violations recorded against the dwm.exe process around the time of suspicious user-mode activity

Detection Strategies

Monitor crash telemetry for faults inside dwmcore.dll or dwm.exe and correlate with the originating local user session
Hunt for non-graphics applications loading or interacting heavily with DWM-related APIs, which is anomalous behavior
Apply behavioral analytics to flag local processes performing reconnaissance patterns such as repeated DWM calls followed by sensitive operations like token manipulation or credential access

Monitoring Recommendations

Forward Windows Event Logs, WER reports, and Sysmon process and module load events into a centralized analytics platform for correlation
Track patch deployment status for Windows DWM updates across endpoints and alert on systems missing the fix
Baseline normal DWM process behavior and alert on deviations such as unexpected child processes or memory access anomalies

How to Mitigate CVE-2026-44814

Immediate Actions Required

Apply the security update referenced in the Microsoft CVE-2026-44814 Advisory to all affected Windows systems
Prioritize patching on multi-user systems, terminal servers, and any host where untrusted users can execute code locally
Audit local account privileges and remove unnecessary interactive logon rights to reduce the population of potential attackers

Patch Information

Microsoft has published the official fix in the Microsoft Security Update Guide. Administrators should deploy the relevant cumulative update for each affected Windows version through Windows Update, Windows Server Update Services (WSUS), Microsoft Update Catalog, or their preferred patch management solution. Confirm successful installation by checking the build number after reboot.

Workarounds

No vendor-supplied workaround is documented; installing the security update is the supported remediation path
Restrict local logon rights and enforce least privilege to limit which users can trigger the vulnerable code path
Enable application allowlisting to prevent unapproved binaries from executing locally and invoking DWM APIs

bash

# Verify Windows build after patch installation
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"

# Confirm the relevant KB is installed (replace KBNNNNNNN with the KB from the Microsoft advisory)
wmic qfe list brief | findstr KBNNNNNNN