CVE-2026-97787

Published: Oct 13, 2026Modified: Oct 16, 2026

7.0

Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitability: 1.0 / Impact: 5.9

Source: secure@microsoft.com (Secondary)

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to elevate privileges locally.

Affected (12)

Products: Microsoft: Windows 11 23h2, Windows 11 24h2, Windows 11 25h2, Windows 11 26h1, Windows 11 26h2, Windows Server 2022, Windows Server 2025

7 products

Configuration A

12 vulnerable

Vulnerable Software	Affected Versions
Microsoft Windows 11 23h2	version < 10.0.22631.7652
Microsoft Windows 11 23h2	version < 10.0.22631.7652
Microsoft Windows 11 24h2	version < 10.0.26100.9711
Microsoft Windows 11 24h2	version < 10.0.26100.9711
Microsoft Windows 11 25h2	version < 10.0.26200.9711
Microsoft Windows 11 25h2	version < 10.0.26200.9711
Microsoft Windows 11 26h1	version < 10.0.28000.3231
Microsoft Windows 11 26h1	version < 10.0.28000.3231
Microsoft Windows 11 26h2	version < 10.0.26300.9711
Microsoft Windows 11 26h2	version < 10.0.26300.9711
Microsoft Windows Server 2022	version < 10.0.20348.5761
Microsoft Windows Server 2025	version < 10.0.26100.33650

Related CWEs

CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97787

Source: secure@microsoft.com

PatchVendor Advisory

Timeline

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