Windows Fast FAT File System Driver Information Disclosure Vulnerability
CVE-2026-70277
Summary
Heap-based buffer overflow in Windows Online Certificate Status Protocol (OCSP) allows an authorized attacker to elevate privileges locally.
Products covered
Windows 10 Version 1809 for 32-bit Systems
Windows 10 Version 1809 for x64-based Systems
Windows Server 2019
Windows Server 2019 (Server Core installation)
Windows Server 2022
Windows Server 2022 (Server Core installation)
Windows Server 2025 (Server Core installation)
Windows Server 2025
Show 8 more products
Windows 10 Version 1607 for 32-bit Systems
Windows 10 Version 1607 for x64-based Systems
Windows Server 2016
Windows Server 2016 (Server Core installation)
Windows Server 2012
Windows Server 2012 (Server Core installation)
Windows Server 2012 R2
Windows Server 2012 R2 (Server Core installation)
Remediation
Install KB5122876. Install KB5122882. Install KB5122871. Install KB5123099. Install KB5123065. Install KB5123066.
Vendor-listed fixes
10.0.17763.9245
10.0.20348.5622
10.0.26100.33438
10.0.14393.9512
6.2.9200.26349
6.3.9600.23398
CVEs in this advisory 1
Update history
What changed in later vendor updates
SecurityAlert records field-level changes from the point we begin following a bulletin. Earlier vendor changes may not have a field-by-field record.
- Added fixed versions: 6.3.9600.23398.
- Removed fixed versions: 6.3.9600.23397.
Updates
- Published by Microsoft Security Response Center
The publication date reported by the vendor.
- Added to SecurityAlert
We collected the advisory from the official source.
- Confirmed at the source
Our collector saw this advisory during a later source check.