CVE-2025-53809 MEDIUM

CVE-2025-53809: Windows Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability

Vendor Microsoft
Product Windows 11 Version 24H2
Weakness CWE-20 · Input validation
Published September 9, 2025
Last update February 20, 2026
View on NVD All CVEs

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

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

What the vulnerability does

01Description

Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.

Key dates

02Disclosure timeline

September 9, 2025 CVE published
February 20, 2026 Record updated