Improper Authentication in Windows SMB Server by Microsoft
CVE-2026-26128

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Windows 10 Version 1607
Windows 10 Version 1809
Windows 10 Version 21h2
Windows 10 Version 22h2
Vendor
CVE Published:
10 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-26128?

A vulnerability in Windows SMB Server allows authorized attackers to exploit improper authentication mechanisms, enabling them to elevate their privileges locally. This weakness can be leveraged to gain unauthorized access and control over sensitive resources within the affected system, presenting significant risks to system integrity and data security.

Affected Version(s)

Windows 10 Version 1607 32-bit Systems 10.0.14393.0 < 10.0.14393.8957

Windows 10 Version 1809 32-bit Systems 10.0.17763.0 < 10.0.17763.8511

Windows 10 Version 21H2 32-bit Systems 10.0.19044.0 < 10.0.19044.7058

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-26128
Created by jarnovandenbrink

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

.