EUVD-2026-56338
GHSA-94mx-chqc-vfg5
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Local low-privilege access required per description; OOB read causes confidentiality disclosure only, with no integrity or availability consequence.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
3DescriptionCVE.org
Out-of-bounds read in Windows DWM Core Library allows an authorized attacker to disclose information locally.
AnalysisAI
Out-of-bounds read in Windows DWM Core Library (Desktop Window Manager) exposes potentially sensitive memory contents to locally authenticated attackers on Windows 11 and Windows Server 2025. The flaw is exploitable by any standard user account without elevated privileges or user interaction, making it a realistic post-access information disclosure primitive for lateral movement or privilege escalation chains. No public exploit code and no KEV listing are identified at time of analysis; SSVC rates exploitation as none and technical impact as partial.
Technical ContextAI
The Windows Desktop Window Manager (DWM) Core Library is a compositing window manager component responsible for rendering the Windows graphical interface, managing visual effects, and compositing application windows. CWE-125 (Out-of-bounds Read) indicates the root cause is a buffer over-read - the library reads beyond the intended bounds of an allocated memory region, potentially exposing adjacent memory contents. Tags include 'Buffer Overflow,' suggesting the underlying memory mismanagement is related to improper bounds checking during DWM compositing or rendering operations. Affected CPE targets include Windows 11 (versions 24H2, 25H2, 26H1) and Windows Server 2025 (including Server Core) as confirmed by ENISA EUVD-2026-56338.
RemediationAI
Apply the Microsoft-released security update addressing CVE-2026-61933, which brings affected builds to 10.0.26100.33296 (Windows Server 2025 and Windows 11 24H2), 10.0.26200.9168 (Windows 11 25H2), or 10.0.28000.2704 (Windows 11 26H1) or later. The patch is available via Windows Update, WSUS, and Microsoft Update Catalog; consult https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-61933 for direct download links. There are no vendor-documented workarounds. Since exploitation requires local low-privilege access, environments unable to patch immediately should enforce least-privilege user accounts, restrict interactive logon rights via Group Policy, and monitor for anomalous local process behavior on affected Windows 11 and Server 2025 endpoints as compensating controls. Note that DWM cannot be disabled without breaking the graphical shell, so component-level mitigation is not practical.
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Same weakness CWE-125 – Out-of-bounds Read
View allSame technique Buffer Overflow
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External POC / Exploit Code
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