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Privacy Statement Third-Party Cookies Accept Reject Manage cookies MSRC  Customer Guidance  Security Update Guide  Vulnerabilities  CVE-2026-42896 Windows DWM Core Library Elevation of Privilege Vulnerability New On this page  CVE-2026-42896  Subscribe RSS PowerShell  API  CSAF Security Vulnerability Released: May 12, 2026 Assigning CNA Microsoft CVE.org link CVE-2026-42896  Impact Elevation of Privilege Max Severity Important Weakness CWE-190: Integer Overflow or Wraparound CWE-122: Heap-based Buffer Overflow CVSS Source Microsoft Vector String CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C Metrics CVSS:3.1 7.8 / 6.8  Base score metrics: 7.8 / Temporal score metrics: 6.8  Expand all  Collapse all Metric Value   Base score metrics(8) Attack Vector Local Attack Complexity Low Privileges Required Low User Interaction None Scope Unchanged Confidentiality High Integrity High Availability High   Temporal score metrics(3) Exploit Code Maturity Unproven Remediation Level Official Fix Report Confidence Confirmed Please see Common Vulnerability Scoring System for more information on the definition of these metrics. Executive Summary Integer overflow or wraparound in Windows DWM Core Library allows an authorized attacker to elevate privileges locally. Exploitability The following table provides an exploitability assessment for this vulnerability at the time of original publication. Publicly disclosed No Exploited No Exploitability assessment Exploitation Less Likely FAQ What privileges could be gained by an attacker who successfully exploited this vulnerability? An attacker who successfully exploited this vulnerability could gain SYSTEM privileges. Acknowledgements namnp with Viettel Cyber Security 𝕏 @ vcslab Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgements for more information. Security Updates To determine the support lifecycle for your software, see the Microsoft Support Lifecycle. Release date Descending  Edit columns  Download  Filters  Product Family  Max Severity  Impact  Platform   Clear Release date  Product Platform Impact Max Severity Article Download Build Number Assigning CNA Customer Action Required Title: Release date, Content: May 12, 2026 Windows 11 Version 26H1 for ARM64-based Systems - Elevation of Privilege Important Title: Knowledge Base Articles for Windows 11 Version 26H1 for ARM64-based Systems, Content:, 1 link 5089548  Title: Download Security Update for Windows 11 Version 26H1 for ARM64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.28000.2113 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required Title: Release date, Content: May 12, 2026 Windows 11 version 26H1 for x64-based Systems - Elevation of Privilege Important Title: Knowledge Base Articles for Windows 11 version 26H1 for x64-based Systems, Content:, 1 link 5089548  Title: Download Security Update for Windows 11 version 26H1 for x64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.28000.2113 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required Title: Release date, Content: May 12, 2026 Windows Server 2025 - Elevation of Privilege Important Title: Knowledge Base Articles for Windows Server 2025, Content:, 2 links 5087539  5087423  Title: Download Security Update for Windows Server 2025, Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26100.32860 10.0.26100.32772 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required Title: Release date, Content: May 12, 2026 Windows 11 Version 24H2 for x64-based Systems - Elevation of Privilege Important Title: Knowledge Base Articles for Windows 11 Version 24H2 for x64-based Systems, Content:, 2 links 5089549  5089466  Title: Download Security Update for Windows 11 Version 24H2 for x64-based Systems, Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26100.8457 10.0.26100.8390 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required Title: Release date, Content: May 12, 2026 Windows 11 Version 24H2 for ARM64-based Systems - Elevation of Privilege Important Title: Knowledge Base Articles for Windows 11 Version 24H2 for ARM64-based Systems, Content:, 2 links 5089549  5089466  Title: Download Security Update for Windows 11 Version 24H2 for ARM64-based Systems, Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26100.8457 10.0.26100.8390 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required Title: Release date, Content: May 12, 2026 Windows 11 Version 25H2 for x64-based Systems - Elevation of Privilege Important Title: Knowledge Base Articles for Windows 11 Version 25H2 for x64-based Systems, Content:, 2 links 5089549  5089466  Title: Download Security Update for Windows 11 Version 25H2 for x64-based Systems, Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26200.8457 10.0.26200.8390 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required Title: Release date, Content: May 12, 2026 Windows 11 Version 25H2 for ARM64-based Systems - Elevation of Privilege Important Title: Knowledge Base Articles for Windows 11 Version 25H2 for ARM64-based Systems, Content:, 2 links 5089549  5089466  Title: Download Security Update for Windows 11 Version 25H2 for ARM64-based Systems, Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26200.8457 10.0.26200.8390 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required Title: Release date, Content: May 12, 2026 Windows Server 2025 (Server Core installation) - Elevation of Privilege Important Title: Knowledge Base Articles for Windows Server 2025 (Server Core installation), Content:, 2 links 5087539  5087423  Title: Download Security Update for Windows Server 2025 (Server Core installation), Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26100.32860 10.0.26100.32772 Title: Assigning CNA, Content: Microsoft Title: Customer action required, Content: Required All results loaded Loaded all 8 rows Disclaimer The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply. Revisions version revisionDate description 1.0 May 12, 2026 Information published.  How satisfied are you with the MSRC Security Update Guide? Rating  Broken  Bad  Below average  Average  Great!  Your Privacy Choices Consumer Health Privacy