CVE-2026-97790

Analyzed Analyzed - Analysis Complete

Improper Link Resolution in Windows Container Isolation FS Filter Driver

Publication date: 2026-10-13

Last updated on: 2026-10-16

Assigner: Microsoft Corporation

Description

Improper link resolution before file access ('link following') in Windows Container Isolation FS Filter Driver (unionfs.sys) allows an authorized attacker to perform tampering locally.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-13

Last Modified

2026-10-16

Generated

2026-10-19

AI Q&A

2026-10-14

EPSS Evaluated

2026-10-18

NVD

CVE-2026-97790

EUVD

EUVD-2026-100310

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2022	to 10.0.20348.5761 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9711 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9711 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9711 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9711 (exc)
microsoft	windows_11_26h1	to 10.0.28000.3231 (exc)
microsoft	windows_11_26h1	to 10.0.28000.3231 (exc)
microsoft	windows_11_26h2	to 10.0.26300.9711 (exc)
microsoft	windows_11_26h2	to 10.0.26300.9711 (exc)
microsoft	windows_server_2025	to 10.0.26100.33650 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-59	The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Attack-Flow Graph

Executive Summary

This vulnerability is an improper link resolution issue in the Windows Container Isolation FS Filter Driver (unionfs.sys). It allows an authorized attacker to perform file tampering locally by exploiting link following before proper access checks.

Impact Analysis

An attacker with local access could modify files within containers, potentially leading to unauthorized changes, data corruption, or privilege escalation. This could disrupt containerized applications or services running on affected systems.

Compliance Impact

This vulnerability allows local tampering via improper link resolution, which could lead to unauthorized file modifications. This may impact compliance by enabling data integrity breaches, potentially violating GDPR's integrity principle or HIPAA's security rule for protected health information.

Mitigation Strategies

Apply the latest security updates from Microsoft to patch the Windows Container Isolation FS Filter Driver (unionfs.sys). Monitor Microsoft's update guide for patches specific to affected Windows versions.

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