Windows Local Security Authority Subsystem Service (LSASS)
CVE-2025-53809 — Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability
Executive Summary
Improper input validation in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to deny service over a network.
Overview
6.5
CVSS MEDIUM
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
Temporal Score: 5.7
EPSS Score
0.01367
probability of exploitation in the next 30 days
0.6827 percentile - updated 2026-06-20
View on FIRST.org
Affected Products
4 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Windows 11 Version 24H2 for ARM64-based Systems | 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) |
Important | Denial of Service | Yes |
| Windows 11 Version 24H2 for x64-based Systems | 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) |
Important | Denial of Service | Yes |
| Windows Server 2025 | 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) |
Important | Denial of Service | Yes |
| Windows Server 2025 (Server Core installation) | 5065426 (Security Update) 5065474 (SecurityHotpatchUpdate) |
Important | Denial of Service | Yes |
Patches
1 patch
| Article | Type | Restart |
|---|---|---|
5065426 (Security Update) 5065474 |
Security Update | Yes |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
References
On This Page