---
id: "CVE-2026-112766"
page: "https://infrastack.ai/live/CVE-2026-112766"
kind: "vulnerability"
aliases: ["CVE-2026-112766"]
title: "Windows exFAT file system: use-after-free lets a local user gain privileges"
severity: "high"
cvss: 7.0
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "Windows 10 1809 / Server 2019", "fixed": ["10.0.17763.9487"], "affected": "< 10.0.17763.9487", "ecosystem": "microsoft"}, {"name": "Windows 10 21H2", "fixed": ["10.0.19044.7846"], "affected": "< 10.0.19044.7846", "ecosystem": "microsoft"}, {"name": "Windows 10 22H2", "fixed": ["10.0.19045.7846"], "affected": "< 10.0.19045.7846", "ecosystem": "microsoft"}, {"name": "Windows 11 23H2", "fixed": ["10.0.22631.7711"], "affected": "< 10.0.22631.7711", "ecosystem": "microsoft"}, {"name": "Windows 11 24H2", "fixed": ["10.0.26100.9974"], "affected": "< 10.0.26100.9974", "ecosystem": "microsoft"}, {"name": "Windows 11 25H2", "fixed": ["10.0.26200.9974"], "affected": "< 10.0.26200.9974", "ecosystem": "microsoft"}, {"name": "Windows 11 26H1", "fixed": ["10.0.28000.3501"], "affected": "< 10.0.28000.3501", "ecosystem": "microsoft"}, {"name": "Windows 11 26H2", "fixed": ["10.0.26300.9974"], "affected": "< 10.0.26300.9974", "ecosystem": "microsoft"}, {"name": "Windows Server 2022", "fixed": ["10.0.20348.5870"], "affected": "< 10.0.20348.5870", "ecosystem": "microsoft"}, {"name": "Windows Server 2025", "fixed": ["10.0.26100.33822"], "affected": "< 10.0.26100.33822", "ecosystem": "microsoft"}]
ecosystems: []
tags: ["exfat", "infrastructure", "local-users", "windows"]
not_affected_if: ["no-local-accounts", "non-windows", "patched-build"]
published_at: "2026-11-10T19:18:40+00:00"
first_seen_at: "2026-11-10T19:24:32+00:00"
updated_at: "2026-11-11T00:09:30+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-112766", "first_seen_at": "2026-11-10T19:24:32+00:00"}, {"source": "analyst", "url": "https://nvd.nist.gov/vuln/detail/cve-2026-112766", "first_seen_at": "2026-11-11T00:09:30+00:00", "cites": ["https://nvd.nist.gov/vuln/detail/cve-2026-112766"]}]
exploit_sources: []
---

# Windows exFAT file system: use-after-free lets a local user gain privileges

Link for people: https://infrastack.ai/live/CVE-2026-112766 (this .md is for agents)

A memory-reuse bug in the Windows exFAT file system driver lets an attacker who already has a local account raise their privileges. Successful exploitation gives the attacker higher rights on the same machine.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- microsoft:Windows 10 1809 / Server 2019 affected < 10.0.17763.9487 fixed 10.0.17763.9487
- microsoft:Windows 10 21H2 affected < 10.0.19044.7846 fixed 10.0.19044.7846
- microsoft:Windows 10 22H2 affected < 10.0.19045.7846 fixed 10.0.19045.7846
- microsoft:Windows 11 23H2 affected < 10.0.22631.7711 fixed 10.0.22631.7711
- microsoft:Windows 11 24H2 affected < 10.0.26100.9974 fixed 10.0.26100.9974
- microsoft:Windows 11 25H2 affected < 10.0.26200.9974 fixed 10.0.26200.9974
- microsoft:Windows 11 26H1 affected < 10.0.28000.3501 fixed 10.0.28000.3501
- microsoft:Windows 11 26H2 affected < 10.0.26300.9974 fixed 10.0.26300.9974
- microsoft:Windows Server 2022 affected < 10.0.20348.5870 fixed 10.0.20348.5870
- microsoft:Windows Server 2025 affected < 10.0.26100.33822 fixed 10.0.26100.33822

## How to check

Run winver or systeminfo (or PowerShell: [System.Environment]::OSVersion.Version, or (Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion').UBR for the revision) and compare the full build number to the fixed builds listed in the fix. A build below the fixed one is exposed. Confirm on the MSRC page for CVE-2026-112766.

## Fix

Install the November 2026 Windows security update that brings your build to at least the fixed build: Win10 1809/Server 2019 10.0.17763.9487; Win10 21H2 10.0.19044.7846; Win10 22H2 10.0.19045.7846; Win11 23H2 10.0.22631.7711; Win11 24H2 10.0.26100.9974; Win11 25H2 10.0.26200.9974; Win11 26H1 10.0.28000.3501; Win11 26H2 10.0.26300.9974; Server 2022 10.0.20348.5870; Server 2025 10.0.26100.33822. KB number not confirmed.

## Timeline

- 2026-11-10T19:24:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-112766
- 2026-11-11T00:09:30+00:00 analyst https://nvd.nist.gov/vuln/detail/cve-2026-112766 — MSRC page not readable by tools; affected builds taken from Microsoft CNA data mirrored on NVD (not primary, nothing marked verified). No exploitation or PoC seen. Fix = the KB for the fixed build; KB number unknown.

## Documents

- [describes] NVD: CVE-2026-112766 (Microsoft CNA data) https://nvd.nist.gov/vuln/detail/cve-2026-112766

## From the sources

Use after free in Windows exFAT File System allows an authorized attacker to elevate privileges locally.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_