AI and data stack advisories

Severe, 6 weeks1496Projects326

1496 severe, 6 weeks · 326 projects

MicrosoftCVE-2026-83999

Microsoft Windows: privilege escalation

Microsoft

CVE-2026-83999 · Published Sep 8, 2026 · updated Sep 11, 2026

High7.0
Fix: upgrade to 10.0.26100.9445 or later (4 fixed versions below)
Microsoft advisory

Improper link resolution before file access ('link following') in Windows Resilient File System (ReFS) Deduplication Service allows an authorized attacker to elevate privileges locally.

Affected versions

PackageAffectedFixed in
Windows 11 Version 24H2
Product
>= 10.0.26100.0, < 10.0.26100.944510.0.26100.9445
Windows 11 Version 25H2
Product
>= 10.0.26200.0, < 10.0.26200.944510.0.26200.9445
Windows 11 version 26H1
Product
>= 10.0.28000.0, < 10.0.28000.295410.0.28000.2954
Windows Server 2025
Product
>= 10.0.26100.0, < 10.0.26100.3343810.0.26100.33438
Windows Server 2025 (Server Core installation)
Product
>= 10.0.26100.0, < 10.0.26100.3343810.0.26100.33438
Details and references
CVSS 3.1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity from
the vendor (its own CVE record or advisory)
Weakness
CWE-59

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