CVE tracker / CVE-2026-78453
CVE-2026-78453
CVE-2026-78453 is the Microsoft Windows SCSI Class System File Information Disclosure Vulnerability. Microsoft rates it Important, CVSS 6.5. It is not in CISA's Known Exploited Vulnerabilities catalog. Published September 8, 2026.
Risk summary
Microsoft describes it: “Integer underflow (wrap or wraparound) in Microsoft Windows SCSI Class System File allows an unauthorized attacker to disclose information over a network.”
How to fix it
Microsoft lists 30 affected products and the update that fixes each:
- KB5122871 · fixed build 10.0.26100.33438
Windows Server 2025, Windows Server 2025 (Server Core installation) - KB5122876 · fixed build 10.0.17763.9245
Windows Server 2019 (Server Core installation), Windows Server 2019, Windows 10 Version 1809 for x64-based Systems, Windows 10 Version 1809 for 32-bit Systems - KB5122878 · fixed build 10.0.19045.7725, 10.0.19044.7725
Windows 10 Version 22H2 for ARM64-based Systems, Windows 10 Version 22H2 for 32-bit Systems, Windows 10 Version 21H2 for x64-based Systems, Windows 10 Version 21H2 for ARM64-based Systems, Windows 10 Version 21H2 for 32-bit Systems, and 1 more - KB5122880 · fixed build 10.0.22631.7582
Windows 11 Version 23H2 for x64-based Systems, Windows 11 Version 23H2 for ARM64-based Systems - KB5122882 · fixed build 10.0.20348.5622
Windows Server 2022 (Server Core installation), Windows Server 2022 - KB5123065 · fixed build 6.2.9200.26349
Windows Server 2012 (Server Core installation), Windows Server 2012 - KB5123066 · fixed build 6.3.9600.23398
Windows Server 2012 R2 (Server Core installation), Windows Server 2012 R2 - KB5123099 · fixed build 10.0.14393.9512
Windows 10 Version 1607 for x64-based Systems, Windows Server 2016 (Server Core installation), Windows 10 Version 1607 for 32-bit Systems, Windows Server 2016 - KB5124008 · fixed build 10.0.26100.9445, 10.0.26200.9445
Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems - KB5124012 · fixed build 10.0.28000.2954
Windows 11 Version 26H1 for ARM64-based Systems, Windows 11 version 26H1 for x64-based Systems
What Microsoft changed
- September 8, 2026: Information published.
- October 7, 2026: Updated an acknowledgement. This is an informational change only.
Details
- Weakness
- CWE-191: Integer Underflow (Wrap or Wraparound)
- Publicly disclosed (Microsoft)
- No
- Exploited (Microsoft)
- No
- Known exploited (CISA KEV)
- Not listed
- Published
- September 8, 2026
- Last revised
- October 7, 2026
Get told when this changes
Senserva Watch emails Microsoft security and patch alerts when something moves: a new exploitation report, a revised fix, a known issue. Free, one email address.
References
From Microsoft, CISA, NVD and FIRST data; the Microsoft details were read when this page was opened. Check the references above before you act.