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Privacy Statement Third-Party Cookies AcceptRejectManage cookies MSRC  Customer Guidance  Security Update Guide  Vulnerabilities  CVE-2026-62815 Microsoft QUIC Remote Code Execution Vulnerability New On this page  CVE-2026-62815  Subscribe RSS PowerShell  API  CSAF Security Vulnerability Released: Aug 11, 2026 Assigning CNA Microsoft CVE.org link CVE-2026-62815  Impact Remote Code Execution Max Severity Critical Weakness CWE-416: Use After Free CVSS Source Microsoft Vector String CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C Metrics CVSS:3.1 9.8 / 8.5  Base score metrics: 9.8 / Temporal score metrics: 8.5  Expand all  Collapse all Metric Value   Base score metrics(8) Attack Vector Network Attack Complexity Low 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 Microsoft QUIC 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 N/A FAQ How could an attacker exploit this vulnerability? An unauthenticated attacker could exploit this vulnerability by sending a specially crafted packet to an affected service over the network. Successful exploitation could allow the attacker to execute code on the target system. No authentication or user interaction is required. Acknowledgements AIフィジカルインターフェイス二号機 𝕏 @ guhe120 pwn2addr 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: Aug 11, 2026 Windows 11 Version 26H1 for ARM64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 Version 26H1 for ARM64-based Systems, Content:, 1 link 5121000  Title: Download Security Update for Windows 11 Version 26H1 for ARM64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.28000.2704 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows 11 version 26H1 for x64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 version 26H1 for x64-based Systems, Content:, 1 link 5121000  Title: Download Security Update for Windows 11 version 26H1 for x64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.28000.2704 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows Server 2025 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2025, Content:, 2 links 5120233  5120228  Title: Download Security Update for Windows Server 2025, Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26100.33296 10.0.26100.33222 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows 11 Version 24H2 for x64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 Version 24H2 for x64-based Systems, Content:, 2 links 5121003  5120994  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: 10.0.26100.9168 10.0.26000.9106 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows 11 Version 24H2 for ARM64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 Version 24H2 for ARM64-based Systems, Content:, 2 links 5121003  5120994  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: 10.0.26100.9168 10.0.26100.9106 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows 11 Version 23H2 for x64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 Version 23H2 for x64-based Systems, Content:, 1 link 5120240  Title: Download Security Update for Windows 11 Version 23H2 for x64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.22631.7517 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows 11 Version 23H2 for ARM64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 Version 23H2 for ARM64-based Systems, Content:, 1 link 5120240  Title: Download Security Update for Windows 11 Version 23H2 for ARM64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.22631.7517 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows 11 Version 25H2 for x64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 Version 25H2 for x64-based Systems, Content:, 2 links 5121003  5120994  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: 10.0.26200.9168 10.0.26100.9106 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows 11 Version 25H2 for ARM64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 11 Version 25H2 for ARM64-based Systems, Content:, 2 links 5121003  5120994  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: 10.0.26200.9168 10.0.26100.9106 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows Server 2025 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2025 (Server Core installation), Content:, 2 links 5120233  5120228  Title: Download Security Update for Windows Server 2025 (Server Core installation), Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.26100.33296 10.0.26100.33222 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows Server 2022 (Server Core installation) - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2022 (Server Core installation), Content:, 2 links 5120242  5120229  Title: Download Security Update for Windows Server 2022 (Server Core installation), Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.20348.5499 10.0.20348.5440 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Aug 11, 2026 Windows Server 2022 - Remote Code Execution Critical Title: Knowledge Base Articles for Windows Server 2022, Content:, 2 links 5120242  5120229  Title: Download Security Update for Windows Server 2022, Content:, 2 links Security Update  Security Hotpatch Update  Title: Build numbers, Content: 10.0.20348.5499 10.0.20348.5440 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 Aug 11, 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 Privacy & Cookies