CVE-2025-55340: Windows Remote Desktop Protocol Security Feature Bypass

Overview

Severity
High (CVSS 7)
CVSS Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category
Security Feature Bypass
Exploit Status
Not Exploited
Exploitation Likelihood
Unlikely
Patch Tuesday
2025-Oct
Released
2025-10-14
EPSS Score
0.04% (percentile: 11.4%)

Description

Improper authentication in Windows Remote Desktop Protocol allows an authorized attacker to bypass a security feature locally.

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 multiple conditions to be met. The attacker must have access to a user's machine and the user must have initiated an RDP session. The attack must also be carried out within a certain amount of time from the initiation of the RDP session. What kind of security feature could be bypassed by successfully exploiting this vulnerability? This vulnerability could allow an attacker to bypass RDP authentication.

Affected Products (19)

Windows

  • Windows 11 Version 25H2 for x64-based Systems
  • Windows 11 Version 25H2 for ARM64-based Systems
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows Server 2025 (Server Core installation)
  • Windows 11 Version 23H2 for ARM64-based Systems
  • Windows 11 Version 23H2 for x64-based Systems
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows 11 Version 24H2 for ARM64-based Systems
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows Server 2025

ESU

  • Windows 11 Version 22H2 for ARM64-based Systems
  • Windows 11 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for 32-bit Systems

Security Updates (5)

Acknowledgments

Toaster

Revision History

  • 2025-10-14: Information published.