What is CVE-2025-59257?

CVE-2025-59257 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. Windows Local Session Manager (LSM) Denial of Service Vulnerability

Which CVE IDs does CVE-2025-59257 cover?

CVE-2025-59257 covers the following CVE IDs: CVE-2025-59257. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2025-59257?

CVE-2025-59257 has a CVSS v3 base score of 6.5, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2025-59257?

CVE-2025-59257 affects 7 products, including: Windows 11 Version 24H2 for ARM64-based Systems; Windows 11 Version 24H2 for x64-based Systems; Windows 11 Version 25H2 for ARM64-based Systems; Windows 11 Version 25H2 for x64-based Systems; Windows Server 2022, 23H2 Edition (Server Core installation); and others — see the full list on the advisory page.

CVE-2025-59257HighCVSS 6.5

Windows Local Session Manager (LSM) Denial of Service Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

October 14, 2025

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2025-59257 →

📋 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 products7

Windows 11 Version 24H2 for ARM64-based Systems
Windows 11 Version 24H2 for x64-based Systems
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 Server 2025
Windows Server 2025 (Server Core installation)

✅ Remediation

KB5066835 (Security Update) — fixed build 10.0.26100.6899 KB5066835 (Security Update) — fixed build 10.0.26200.6899 KB5066780 (Security Update) — fixed build 10.0.25398.1913

🔗 References (5)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-59257
patchhttps://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5066835
referencehttps://support.microsoft.com/help/5066835
patchhttps://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB5066780
referencehttps://support.microsoft.com/help/5066780