CVE-2026-78446: Windows Distributed File System (DFS) Denial of Service Vulnerability
Use after free in Windows Distributed File System (DFS) allows an authorized attacker to deny service over a network.
Other sources
Windows Distributed File System (DFS) Denial of Service Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26349Patch KB5123065 - Upgrade
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Fixed in 6.3.9600.23397Patch KB5123066 - Upgrade
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Fixed in 10.0.14393.9512Patch KB5123099 - Upgrade
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Fixed in 10.0.28000.2954Patch KB5124012 - Upgrade
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Fixed in 10.0.22631.7582Patch KB5122880 - Upgrade
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Fixed in 10.0.26100.9445Patch KB5124008 - Upgrade
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Fixed in 10.0.26200.9445Patch KB5124008 - Upgrade
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Fixed in 10.0.26100.33438Patch KB5122871 - Upgrade
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Fixed in 10.0.19045.7725Patch KB5122878 - Upgrade
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Fixed in 10.0.19044.7725Patch KB5122878 - Upgrade
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Fixed in 10.0.20348.5622Patch KB5122882 - Upgrade
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Fixed in 10.0.17763.9245Patch KB5122876
Event History
Frequently Asked Questions
Who can exploit this vulnerability?
An attacker must be authorized and have network access to the affected Windows system. The available information does not indicate that unauthenticated attackers can exploit it.
What is the expected impact of successful exploitation?
Successful exploitation can deny service on the affected system. The supplied severity vector indicates no confidentiality or integrity impact.
Which systems should be reviewed for exposure?
Review Microsoft Windows 10, Windows 11, and Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025 systems that use Distributed File System (DFS) and are reachable by authorized network users.