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Use-After-Free in Microsoft Brokering File System Lets Authorized User Escalate Privileges

Last refreshed2026-09-26

Status: UPDATED  |  Advisory ID: CVE-2026-26181

Key Details

CVECVE-2026-26181
CVSS Score / Version7.8 (High) / CVSS v3.1
Updated2026-09-24
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS Proseattack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is high; availability impact is high.
Affected productssee table below
Classified asCWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'))
Exploitation prediction (EPSS)0.26% probability of exploitation in the next 30 days (15% percentile) -- FIRST.org's EPSS model.

Affected Products, Subsystems & Sectors

VendorProductAffected VersionsPatch Status
MicrosoftWindows 11 (version 23H2)
MicrosoftWindows 11 (version 24H2)
MicrosoftWindows 11 (version 25H2)
MicrosoftWindows 11 (version 26H1)
MicrosoftWindows Server 2025
MicrosoftWindows Server 2022 (version 23H2)
SubsystemsCore Infrastructure, EWS Workstation Delivery/Virtualization
SectorsAll Sectors

What to Know

Use after free in Microsoft Brokering File System allows an authorized attacker to elevate privileges locally.

What to Do

Monitor Microsoft's web page for any future patch releases. See vendor advisory link below.

References

SourceReference
NVDhttps://nvd.nist.gov/vuln/detail/CVE-2026-26181
CVEhttps://www.cve.org/CVERecord?id=CVE-2026-26181
Vendor advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26181