MSRC-CVE-2026-62799 — Windows SMB Client Elevation of Privilege Vulnerability

Summary

Impact: Elevation of Privilege. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.

Details

What privileges could be gained by an attacker who successfully exploited this vulnerability?
An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.

Security updates
10.0.28000.2704 — https://support.microsoft.com/help/5121000

Vulnerabilities 1

High 7.8

CVE-2026-62799

Windows SMB Client Elevation of Privilege Vulnerability

Heap-based buffer overflow in Windows SMB Client allows an authorized attacker to elevate privileges locally.

Microsoft Windows 11 version 26H1 Windows

Aug 11, 2026

Revision history

2026-09-11 #2
Updated an acknowledgement. This is an informational change only.
2026-08-11 #1
Information published.

References

CVE-2026-62799 Windows SMB Client Elevation of Privilege Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-62799
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
Common Vulnerability Scoring System
https://www.first.org/cvss