CVE-2026-85826: Windows Fast FAT Driver Elevation of Privilege Vulnerability
Out-of-bounds write in Windows Fast FAT Driver allows an authorized attacker to elevate privileges locally.
Other sources
Windows Fast FAT Driver Elevation of Privilege 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 10.0.26300.9711Patch KB5127648 - Upgrade
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Fixed in 6.2.9200.26434Patch KB5126835 - Upgrade
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Fixed in 10.0.14393.9612Patch KB5126868 - Upgrade
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Fixed in 10.0.28000.3231Patch KB5127646 - Upgrade
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Fixed in 6.3.9600.23470Patch KB5126836 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.9711Patch KB5127648 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.33650Patch KB5126646 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.22631.7652Patch KB5126653 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.19044.7807Patch KB5126657 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26200.9711Patch KB5127648 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.20348.5761Patch KB5126655 - Upgrade
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Fixed in 10.0.17763.9376Patch KB5126651
Event History
Frequently Asked Questions
Who can exploit this vulnerability?
An attacker must already be authorized on the affected Windows system and must exploit it locally. The provided data does not indicate that remote, unauthenticated exploitation is possible.
Which systems should be prioritized for review?
Review systems running Microsoft Windows 10 or Windows 11, and Windows Server 2012, 2012 R2, 2016, 2019, 2022, or 2025. The vulnerability can result in elevation of privilege with high impacts to confidentiality, integrity, and availability.
Does exploitation require user interaction?
No user interaction is required according to the supplied vector. Exploitation does require low-level attacker privileges and has high attack complexity.