CVE-2026-54990: Remote Desktop Client Remote Code Execution Vulnerability

Overview

Severity
Critical (CVSS 9.8)
CVSS Vector
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
Category
Remote Code Execution
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2026-Jul
Released
2026-07-14
EPSS Score
0.82% (percentile: 54.2%)

Description

Heap-based buffer overflow in Remote Desktop Client allows an unauthorized attacker to execute code over a network.

FAQ

How could an attacker exploit this vulnerability? An attacker could exploit this vulnerability by persuading a user to connect to a malicious Remote Desktop Protocol (RDP) server using a vulnerable RDP client. The malicious server could send specially crafted responses that trigger memory corruption on the client system, potentially allowing arbitrary code execution in the context of the logged-on user. Successful exploitation requires user interaction to establish the RDP connection.

Affected Products (8)

Windows

  • Windows Server 2025 (Server Core installation)
  • Windows 11 Version 25H2 for ARM64-based Systems
  • Windows 11 Version 25H2 for x64-based Systems
  • Windows 11 Version 24H2 for ARM64-based Systems
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows Server 2025
  • Windows 11 version 26H1 for x64-based Systems
  • Windows 11 Version 26H1 for ARM64-based Systems

Security Updates (3)

Acknowledgments

<a href="https://x.com/hareh4ru">Kyeongmin Kim (@hareh4ru)</a> with <a href="https://kaist-hacking.github.io/">KAIST Hacking Lab</a>, pwn2addr, Thanatos Tian &amp; PB18 &amp; @2st__ with Diffract

Revision History

  • 2026-07-14: Information published.