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Windows SMB Server Elevation of Privilege vulnerabilities

12/01/2026 - Download

Product

Windows

Severity

High

Fixed Version(s)

See Microsoft advisories

Affected Version(s)

See Microsoft advisories

Authors

Guillaume André

Description

Presentation

Windows is a product line of proprietary graphical operating systems developed and marketed by Microsoft.

Issue(s)

A lack of check in Windows SMB server allows an authenticated attacker to perform a reflection attack to elevate privileges locally on any Windows machine which does not enforce SMB signing.

Timeline

Date Description
2025.10.05 First advisory sent to MSRC
2025.10.31 Second advisory sent to MSRC
2025.12.02 First vulnerability acknowledged by Microsoft
2026.02.19 Second vulnerability acknowledged by Microsoft
2026.03.10 Patch published by Microsoft in March 2026 Patch Tuesday
2026.05.01 Public release of this advisory

 

Technical details

Description

The complete analysis of the vulnerabilities can be found in the associated blogposts:

Impact

An authenticated attacker can elevate privileges locally on any Windows machine which does not enforce SMB signing.