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Privacy Statement Third-Party Cookies AcceptRejectManage cookies MSRC  Customer Guidance  Security Update Guide  Vulnerabilities  CVE-2026-44801 Remote Desktop Client Remote Code Execution Vulnerability New On this page  CVE-2026-44801  Subscribe RSS PowerShell  API  CSAF Security Vulnerability Released: Jun 9, 2026 Assigning CNA Microsoft CVE.org link CVE-2026-44801  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:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C Metrics CVSS:3.1 7.5 / 6.5  Base score metrics: 7.5 / Temporal score metrics: 6.5  Expand all  Collapse all Metric Value   Base score metrics(8) Attack Vector Network Attack Complexity High Privileges Required None User Interaction Required 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 Heap-based buffer overflow in Remote Desktop Client 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 take additional actions prior to exploitation to prepare the target environment. How could an attacker exploit this vulnerability? In the case of a Remote Desktop connection, an attacker with control of a Remote Desktop Server could trigger a remote code execution (RCE) on the machine when a victim connects to the attacking server with the vulnerable Remote Desktop Client. Acknowledgements Kyeongmin Kim (@hareh4ru) 𝕏 @ hareh4ru with KAIST Hacking Lab https://kaist-hacking.github.io/ 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 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:, 1 link 5094126  Title: Download Security Update for Windows 11 Version 25H2 for x64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.26200.8655 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 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:, 1 link 5094126  Title: Download Security Update for Windows 11 Version 25H2 for ARM64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.26200.8655 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 10 Version 22H2 for 32-bit Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 22H2 for 32-bit Systems, Content:, 1 link 5094127  Title: Download Security Update for Windows 10 Version 22H2 for 32-bit Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.19045.7417 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows 10 Version 22H2 for ARM64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 22H2 for ARM64-based Systems, Content:, 1 link 5094127  Title: Download Security Update for Windows 10 Version 22H2 for ARM64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.19045.7417 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows 10 Version 22H2 for x64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 22H2 for x64-based Systems, Content:, 1 link 5094127  Title: Download Security Update for Windows 10 Version 22H2 for x64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.19045.7417 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows 10 Version 21H2 for x64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 21H2 for x64-based Systems, Content:, 1 link 5094127  Title: Download Security Update for Windows 10 Version 21H2 for x64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.19044.7417 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows 10 Version 21H2 for ARM64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 21H2 for ARM64-based Systems, Content:, 1 link 5094127  Title: Download Security Update for Windows 10 Version 21H2 for ARM64-based Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.19044.7417 Title: Assigning CNA, Content: Microsoft Title: Release date, Content: Jun 9, 2026 Windows 10 Version 21H2 for 32-bit Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 21H2 for 32-bit Systems, Content:, 1 link 5094127  Title: Download Security Update for Windows 10 Version 21H2 for 32-bit Systems, Content:, 1 link Security Update  Title: Build numbers, Content: 10.0.19044.7417 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 Remote Desktop client for Windows Desktop - Remote Code Execution Critical Title: Knowledge Base Articles for Remote Desktop client for Windows Desktop, Content:, 1 link Release Notes  Title: Download Security Update for Remote Desktop client for Windows Desktop, Content:, 1 link Security Update  Title: Build numbers, Content: 1.2.7214.0 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 Title: Release date, Content: Jun 9, 2026 Windows 10 Version 1809 for x64-based Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 1809 for x64-based Systems, Content:, 1 link 5094123  Title: Download Security Update for Windows 10 Version 1809 for x64-based Systems, 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 10 Version 1809 for 32-bit Systems - Remote Code Execution Critical Title: Knowledge Base Articles for Windows 10 Version 1809 for 32-bit Systems, Content:, 1 link 5094123  Title: Download Security Update for Windows 10 Version 1809 for 32-bit Systems, 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 App Client for Windows Desktop - Remote Code Execution Critical Title: Knowledge Base Articles for Windows App Client for Windows Desktop