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Privacy Statement Third-Party Cookies AcceptRejectManage cookies MSRC  Customer Guidance  Security Update Guide  Vulnerabilities  CVE-2026-42987 Windows Deployment Services (WDS) Remote Code Execution New On this page  CVE-2026-42987  Subscribe RSS PowerShell  API  CSAF Security Vulnerability Released: Jun 9, 2026 Assigning CNA Microsoft CVE.org link CVE-2026-42987  Impact Remote Code Execution Max Severity Critical Weakness CWE-416: Use After Free CVSS Source Microsoft Vector String CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C Metrics CVSS:3.1 8.1 / 7.1  Base score metrics: 8.1 / Temporal score metrics: 7.1  Expand all  Collapse all Metric Value   Base score metrics(8) Attack Vector Network Attack Complexity High Privileges Required None 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 Use after free in Windows Deployment Services allows an unauthorized attacker to execute code over a network. 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 According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability? Successful exploitation of this vulnerability requires an attacker to win a race condition. How could an attacker exploit this vulnerability? An attacker could send specially crafted network requests to a Windows Server system that has the Windows Deployment Services (WDS) role enabled and is listening for TFTP traffic. By triggering an error in how the server handles simultaneous requests, an unauthenticated remote attacker could cause the service to use invalid memory, which could allow the attacker to run code on the affected server. Acknowledgements R4nger with Kunlun Lab & Zhiniang Peng with HUST 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 Title: Release date, Content: Jun 9, 2026 Windows Server 2012 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2012 (Server Core installation), Content:, 1 link 5094042  Title: Download Security Update for Windows Server 2012 (Server Core installation), Content:, 1 link Monthly Rollup  Title: Build numbers, Content: 6.2.9200.26132 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2012 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2012, Content:, 1 link 5094042  Title: Download Security Update for Windows Server 2012, Content:, 1 link Monthly Rollup  Title: Build numbers, Content: 6.2.9200.26132 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2012 R2 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2012 R2 (Server Core installation), Content:, 1 link 5094041  Title: Download Security Update for Windows Server 2012 R2 (Server Core installation), Content:, 1 link Monthly Rollup  Title: Build numbers, Content: 6.3.9600.23228 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2012 R2 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2012 R2, Content:, 1 link 5094041  Title: Download Security Update for Windows Server 2012 R2, Content:, 1 link Monthly Rollup  Title: Build numbers, Content: 6.3.9600.23228 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2016 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2016 (Server Core installation), Content:, 1 link 5094122  Title: Download Security Update for Windows Server 2016 (Server Core installation), Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.14393.9234 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2016 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2016, Content:, 1 link 5094122  Title: Download Security Update for Windows Server 2016, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.14393.9234 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2025 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2025, Content:, 1 link 5094125  Title: Download Security Update for Windows Server 2025, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.26100.32995 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2025 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2025 (Server Core installation), Content:, 1 link 5094125  Title: Download Security Update for Windows Server 2025 (Server Core installation), Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.26100.32995 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2022 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2022 (Server Core installation), Content:, 1 link 5094128  Title: Download Security Update for Windows Server 2022 (Server Core installation), Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.20348.5256 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2022 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2022, Content:, 1 link 5094128  Title: Download Security Update for Windows Server 2022, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.20348.5256 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2019 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2019 (Server Core installation), Content:, 1 link 5094123  Title: Download Security Update for Windows Server 2019 (Server Core installation), Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.17763.8880 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows Server 2019 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2019, Content:, 1 link 5094123  Title: Download Security Update for Windows Server 2019, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.17763.8880 Title: Assigning CNA, Content: Microsoft All results loaded Loaded all 12 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 Jun 9, 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