CVE-2026-70133: Windows SMB Server Denial of Service Vulnerability
Allocation of resources without limits or throttling in Windows SMB Server allows an unauthorized attacker to deny service over a network.
Other sources
Windows SMB Server 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 6.3.9600.23470Patch KB5126836 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26434Patch KB5126835 - Upgrade
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Fixed in 10.0.19044.7807Patch KB5126657 - Upgrade
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Fixed in 10.0.14393.9612Patch KB5126868 - Upgrade
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Fixed in 10.0.20348.5761Patch KB5126655 - Upgrade
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Fixed in 10.0.17763.9376Patch KB5126651 - Upgrade
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Fixed in 10.0.26100.33650Patch KB5126646 - Upgrade
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Fixed in 10.0.22631.7652Patch KB5126653 - Upgrade
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Fixed in 10.0.26200.9711Patch KB5127648 - Upgrade
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Fixed in 10.0.28000.3231Patch KB5127646 - Upgrade
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Fixed in 10.0.26100.9711Patch KB5127648 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26300.9711Patch KB5127648
Event History
Frequently Asked Questions
Who can exploit this issue?
An unauthorized attacker can exploit it remotely over a network. No privileges or user interaction are required.
What is the expected impact of a successful attack?
Successful exploitation can deny service through uncontrolled resource allocation in Windows SMB Server. The provided severity vector indicates availability impact only, with no stated confidentiality or integrity impact.
Which systems should be prioritized for review?
Review systems running the listed Windows 10, Windows 11, or Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025 products where the Windows SMB Server service is exposed to network attackers.