CVE-2025-59257: Windows Local Session Manager (LSM) Denial of Service Vulnerability

Overview

Severity
Medium (CVSS 6.5)
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C
Category
Denial of Service
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2025-Oct
Released
2025-10-14
EPSS Score
0.21% (percentile: 43.1%)

Description

Improper validation of specified type of input in Windows Local Session Manager (LSM) allows an authorized attacker to deny service over a network.

Affected Products (7)

Windows

  • Windows Server 2025 (Server Core installation)
  • Windows 11 Version 25H2 for ARM64-based Systems
  • Windows 11 Version 25H2 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

Security Updates (2)

Acknowledgments

Hussein Alrubaye with Microsoft

Revision History

  • 2025-10-14: Information published.