High MSRC-CVE-2026-78446 1 CVE

Windows Distributed File System (DFS) Remote Code Execution Vulnerability

Published Sep 8, 2026 · Updated Oct 5, 2026 · Revision 2

Vendor: Microsoft

Summary

Impact: Remote Code Execution. Microsoft rating: Important. Not known to be exploited — Exploitation Unlikely. Customer action: Required.

Details

Security updates
10.0.17763.9245 — https://support.microsoft.com/help/5122876
10.0.20348.5622 — https://support.microsoft.com/help/5122882
10.0.19044.7725 — https://support.microsoft.com/help/5122878
10.0.26100.33438 — https://support.microsoft.com/help/5122871
10.0.26200.9445 — https://support.microsoft.com/help/5124008
10.0.22631.7582 — https://support.microsoft.com/help/5122880
10.0.28000.2954 — https://support.microsoft.com/help/5124012
10.0.14393.9512 — https://support.microsoft.com/help/5123099
6.2.9200.26349 — https://support.microsoft.com/help/5123065
6.3.9600.23398 — https://support.microsoft.com/help/5123066

Vulnerabilities 1

High 7.5

CVE-2026-78446

Windows Distributed File System (DFS) Remote Code Execution Vulnerability

Use after free in Windows Distributed File System (DFS) allows an authorized attacker to execute code over a network.

Microsoft Windows Server 2019 Windows Server 2019 (Server Core installation) Windows 10 Version 1809 Windows

Sep 8, 2026

Revision history

2026-10-05 #2
Updated Impact in the Security Updates table, CVE Title, and FAQs. This is an informational change only.
2026-09-08 #1
Information published.

References

CVE-2026-78446 Windows Distributed File System (DFS) Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78446
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