CVE-2026-83516ImportantDoSNetwork
Windows Local Security Authority Subsystem Service (LSASS) Denial of Service Vulnerability
Assessment
Out-of-bounds read in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.
- Severity
- Important
- CVSS base score
- 7.5CVSS:3.1/
AV:N/ AC:L/ PR:N/ UI:N/ S:U/ C:N/ I:N/ A:H/ E:U/ RL:O/ RC:C - Impact
- Denial of Service
- EPSS, next 30 days
- Not scored yet
- Public exploit code
- No Nuclei template lists it
- Exploitability
- Exploitation Unlikely
- Publicly disclosed
- No
- Customer action
- Required: apply the update
- Component
- Windows Local Security Authority Subsystem Service (LSASS)
- Weakness
- CWE-125: Out-of-bounds Read
- Issued by
- Microsoft
- Published
- 13 Oct 2026 · October 2026
- Last revised
- 13 Oct 2026
CVSS 3.1 base metricsRed raises the risk · green lowers it
- Attack vector
- NetworkAV:N
- Attack complexity
- LowAC:L
- Privileges required
- NonePR:N
- User interaction
- NoneUI:N
- Scope
- UnchangedS:U
- Confidentiality
- NoneC:N
- Integrity
- NoneI:N
- Availability
- HighA:H
Updates that fix it
5 KBs| KB | Type | Restart | Applies to | Other CVEs |
|---|---|---|---|---|
| KB5126646 | Security Update | Required | Windows Server 2025, Windows Server 2025 (Server Core installation) | All CVEs in KB5126646 |
| KB5126651 | Security Update | Required | Windows 10 Version 1809 for 32-bit Systems, Windows 10 Version 1809 for x64-based Systems, Windows Server 2019 and 1 more | All CVEs in KB5126651 |
| KB5126655 | Security Update | Required | Windows Server 2022, Windows Server 2022 (Server Core installation) | All CVEs in KB5126655 |
| KB5127646 | Security Update | Required | Windows 11 Version 26H1 for ARM64-based Systems, Windows 11 version 26H1 for x64-based Systems | All CVEs in KB5127646 |
| KB5127648 | Security Update | Required | Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems and 3 more | All CVEs in KB5127648 |
Affected products
Windows16 affected products
- Windows 10 Version 1809 for 32-bit Systems
- Windows 10 Version 1809 for x64-based Systems
- 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 11 Version 26H1 for ARM64-based Systems
- Windows 11 version 26H1 for x64-based Systems
- Windows 11 Version 26H2 for ARM64-based Systems
- Windows 11 Version 26H2 for x64-based Systems
- Windows Server 2019
- Windows Server 2019 (Server Core installation)
- Windows Server 2022
- Windows Server 2022 (Server Core installation)
- Windows Server 2025
- Windows Server 2025 (Server Core installation)
What changed
First observed 14 Oct 2026No field changes in the recorded history.
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