CVE-2025-48004: Windows 11 22h2 Privilege Escalation Flaw

CVE-2025-48004 Overview

CVE-2025-48004 is a use-after-free vulnerability [CWE-416] in the Microsoft Brokering File System. The flaw allows an authenticated local attacker to elevate privileges on affected Windows systems. Successful exploitation grants attackers access to resources normally reserved for higher-privileged accounts, including SYSTEM-level operations.

Microsoft published the advisory on October 14, 2025. The vulnerability affects multiple supported versions of Windows 11 and Windows Server. While the attack complexity is rated high, the confidentiality, integrity, and availability impacts are all rated high.

Critical Impact
Local privilege escalation to SYSTEM through memory corruption in a core Windows kernel-mode component, enabling full compromise of the host after initial low-privilege access.

Affected Products

Microsoft Windows 11 (22H2, 23H2, 24H2, 25H2)
Microsoft Windows Server 2022 23H2
Microsoft Windows Server 2025

Discovery Timeline

2025-10-14 - CVE-2025-48004 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-48004

Vulnerability Analysis

The vulnerability resides in the Microsoft Brokering File System, a Windows component that mediates file system operations between processes with different privilege levels. A use-after-free condition [CWE-416] occurs when the component references a memory object after it has been freed. An attacker who wins the required race condition can control the freed memory region and trigger execution paths that operate on attacker-controlled data.

The attack is local and requires low privileges but no user interaction. Exploitation results in privilege escalation to SYSTEM, giving the attacker full control of the affected host. Microsoft has not published detailed technical internals, and no public proof-of-concept exists at the time of writing.

Root Cause

The Brokering File System fails to correctly manage the lifetime of an internal memory object. Under specific timing conditions, one code path frees the object while another retains and dereferences the stale pointer. This reuse of freed memory permits an attacker to place controlled data at the previous allocation, corrupting subsequent operations.

Attack Vector

An attacker must already have code execution on the target with standard user privileges. The exploit triggers concurrent operations against the Brokering File System to force the free-then-reuse condition. Success yields elevated privileges, allowing the attacker to disable security tooling, install persistence, or move laterally. This class of local elevation-of-privilege is frequently chained after initial access from phishing, malicious documents, or a browser exploit.

See the Microsoft CVE-2025-48004 Advisory for vendor-supplied details.

Detection Methods for CVE-2025-48004

Indicators of Compromise

Unexpected child processes spawned by low-privilege parents that immediately execute as NT AUTHORITY\SYSTEM.
Crashes or Windows Error Reporting entries referencing the Brokering File System driver on affected Windows 11 or Windows Server 2022/2025 hosts.
Anomalous access to sensitive registry hives or protected file paths shortly after a standard-user process launch.

Detection Strategies

Hunt for token manipulation and process-integrity level changes originating from user-mode processes without a legitimate elevation path.
Correlate suspicious NtCreateFile or broker-related IOCTL activity with subsequent privileged actions on the same host.
Monitor for exploitation primitives common to use-after-free chains, including heap-spray patterns and repeated crash-recover loops.

Monitoring Recommendations

Enable Windows kernel and Sysmon logging for process creation (Event ID 1) and process access (Event ID 10), and forward to a centralized analytics platform.
Baseline expected privilege transitions per user and alert on deviations, particularly SYSTEM inheritance from interactive sessions.
Track patch compliance across Windows 11 and Windows Server 2022/2025 endpoints to identify unpatched hosts exposed to local attackers.

How to Mitigate CVE-2025-48004

Immediate Actions Required

Apply the October 2025 Microsoft security updates to all affected Windows 11 and Windows Server systems without delay.
Prioritize patching on multi-user systems, terminal servers, and virtual desktop infrastructure where local attackers are more likely.
Restrict interactive and remote logon rights on high-value servers to reduce the pool of accounts that can trigger local exploitation.

Patch Information

Microsoft released fixes as part of the October 2025 Patch Tuesday cycle. Refer to the Microsoft CVE-2025-48004 Advisory for the specific KB articles and cumulative updates that correspond to each affected Windows build.

Workarounds

No official workaround has been published by Microsoft. Patching is the required remediation.
Enforce the principle of least privilege and remove local administrator rights from standard user accounts to limit follow-on impact.
Apply application allowlisting to block untrusted binaries that could serve as the initial-access stage before local elevation.

bash

# Verify installed updates on a Windows host
wmic qfe list brief /format:table

# PowerShell: list hotfixes installed on or after October 2025 Patch Tuesday
Get-HotFix | Where-Object { $_.InstalledOn -ge (Get-Date '2025-10-14') }