CVE-2026-45637 Overview
CVE-2026-45637 is a use-after-free vulnerability [CWE-416] in the Windows Desktop Window Manager (DWM) Core Library. An authorized local attacker can leverage the flaw to elevate privileges on an affected Windows system. Microsoft published the advisory through the Microsoft Security Response Center (MSRC).
The vulnerability carries a CVSS 3.1 base score of 7.8 and requires local access with low privileges. Successful exploitation results in high impact to confidentiality, integrity, and availability. No public proof-of-concept code or active exploitation has been reported as of publication.
Critical Impact
A local attacker with standard user rights can escalate to higher privileges by triggering a use-after-free condition in the DWM Core Library.
Affected Products
- Windows operating systems incorporating the DWM Core Library (see the Microsoft CVE-2026-45637 Advisory for the full version list)
- Desktop Window Manager component (dwmcore.dll)
- Windows graphics subsystem dependent on DWM
Discovery Timeline
- 2026-06-09 - CVE-2026-45637 published to NVD
- 2026-06-09 - Last updated in NVD database
Technical Details for CVE-2026-45637
Vulnerability Analysis
The vulnerability resides in the Windows Desktop Window Manager (DWM) Core Library, the component responsible for compositing and rendering desktop graphics. The flaw is classified as a use-after-free condition [CWE-416], where memory is referenced after it has been released.
When DWM processes graphics objects, an object reference can persist after the underlying memory has been freed. An attacker who controls subsequent allocations can place attacker-influenced data into the freed region. The dangling pointer then dereferences attacker-controlled content during later DWM operations.
Because DWM runs with elevated privileges in the Windows session, controlled corruption of its internal state can lead to privilege escalation from a standard user context to higher integrity levels.
Root Cause
The root cause is improper object lifetime management within the DWM Core Library. The component releases a graphics object while another code path still holds a reference to it. The subsequent use of the freed reference enables memory corruption.
Attack Vector
Exploitation requires local access and low privileges. The attacker runs code on the target host as an authenticated user. No user interaction is required beyond the attacker's own session activity. The attacker triggers a sequence of DWM operations that frees an object, sprays the heap to control the freed region, then invokes the code path that dereferences the stale pointer. Successful exploitation yields code execution at DWM's privilege level.
No verified public exploitation code is available. Technical details are limited to Microsoft's advisory.
Detection Methods for CVE-2026-45637
Indicators of Compromise
- Unexpected crashes of dwm.exe or modules loaded by the Desktop Window Manager process
- Application Error events (Event ID 1000) referencing dwmcore.dll access violations
- New processes spawned from dwm.exe or token manipulation associated with the DWM process
Detection Strategies
- Monitor for abnormal child processes or thread injection targeting dwm.exe
- Correlate DWM process crashes with subsequent privileged process creation by the same user session
- Track loading of unsigned or unusual modules into the DWM process address space
Monitoring Recommendations
- Enable Windows Error Reporting telemetry collection for DWM crashes across endpoints
- Forward Sysmon Event ID 10 (ProcessAccess) and Event ID 8 (CreateRemoteThread) targeting dwm.exe to a central SIEM
- Baseline normal DWM behavior per host so anomalous memory access patterns surface quickly
How to Mitigate CVE-2026-45637
Immediate Actions Required
- Apply the Microsoft security update referenced in the Microsoft CVE-2026-45637 Advisory as soon as it is available for the affected build
- Inventory Windows hosts to identify systems running vulnerable DWM Core Library versions
- Prioritize patching on multi-user systems such as Remote Desktop Session Hosts and shared workstations
Patch Information
Microsoft addresses CVE-2026-45637 through its standard security update channel. Refer to the Microsoft CVE-2026-45637 Advisory for the specific KB articles, supported builds, and update package identifiers. Deploy the update through Windows Update, Windows Server Update Services (WSUS), or your configuration management platform.
Workarounds
- No official workaround has been published; apply the vendor patch as the primary remediation
- Restrict interactive logon rights on sensitive systems to reduce the population of users who can launch local exploitation
- Enforce application control policies (such as Windows Defender Application Control) to limit execution of untrusted binaries that could trigger the vulnerable code path
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
