---
id: CVE-2026-97810
title: >-
  Heap-based buffer overflow in Windows Container Isolation FS Filter Driver
  (unionfs.sys) allows an authorized attacker to elevate privileges locally.
summary: >-
  Heap-based buffer overflow in Windows Container Isolation FS Filter Driver
  (unionfs.sys) allows an authorized attacker to elevate privileges locally.
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-122
published: '2026-10-13'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T23:19:34.930'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97810'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97810'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-13T19:43:29.310Z'
vendor: Microsoft
product: Windows 11 Version 24H2
affected:
  - windows_11_version_24h2 >= 10.0.26100.0 < 10.0.26100.9711
  - windows_11_version_25h2 >= 10.0.26200.0 < 10.0.26200.9711
  - windows_11_version_26h1 >= 10.0.28000.0 < 10.0.28000.3231
  - windows_11_version_26h2 >= 10.0.26300.0 < 10.0.26300.9711
  - windows_server_2022 >= 10.0.20348.0 < 10.0.20348.5761
  - windows_server_2025 >= 10.0.26100.0 < 10.0.26100.33650
  - >-
    windows_server_2025_server_core_installation >= 10.0.26100.0 <
    10.0.26100.33650
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-13T21:58:11.857993Z'
---

## Overview

Heap-based buffer overflow in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to elevate privileges locally.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.