CVE-2026-78453: Microsoft Windows SCSI Class System File Information Disclosure Vulnerability

Overview

Severity

Medium (CVSS 6.5)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C

Category

Information Disclosure

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2026-Sep

Released

2026-09-08

Last Updated

2026-10-07

EPSS Score

0.92% (percentile: 60.0%)

Description

Integer underflow (wrap or wraparound) in Microsoft Windows SCSI Class System File allows an unauthorized attacker to disclose information over a network.

FAQ

What type of information could be disclosed by this vulnerability? An attacker who successfully exploited this vulnerability could view heap memory from a privileged process running on the server.

Affected Products (30)

Windows

• 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 10 Version 21H2 for 32-bit Systems
• Windows 10 Version 21H2 for ARM64-based Systems
• Windows 10 Version 21H2 for x64-based Systems
• Windows Server 2025 (Server Core installation)
• Windows 11 Version 25H2 for ARM64-based Systems
• Windows 11 Version 25H2 for x64-based Systems
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows Server 2025
• Windows 11 version 26H1 for x64-based Systems
• Windows 11 Version 26H1 for ARM64-based Systems
• 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)

ESU

• Windows 10 Version 22H2 for x64-based Systems
• Windows 10 Version 22H2 for ARM64-based Systems
• Windows 10 Version 22H2 for 32-bit Systems
• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (10)

• 5122876
• 5122882
• 5122878
• 5122871
• 5124008
• 5122880
• 5124012
• 5123099
• 5123065
• 5123066

Acknowledgments

<a href="https://mylostchristmas.tistory.com/20">Seung Chan Kim</a>, yhw, <a href="https://ch.linkedin.com/in/rafael-scheel-b0a10b43">Rafael Scheel</a> with <a href="https://www.oneconsult.com/">Oneconsult AG</a>, Takuto Tanda with <a href="https://gmo-cybersecurity.com/en/">GMO Cybersecurity by Ierae, Inc.</a>, Linzishan, Anemone, Zhiniang Peng with HUST

Revision History

• 2026-09-08: Information published.
• 2026-10-07: Updated an acknowledgement. This is an informational change only.