CVE-2025-62569 Overview
CVE-2025-62569 is a use-after-free vulnerability [CWE-416] in the Microsoft Brokering File System. An authorized local attacker can exploit the flaw to elevate privileges on affected Windows systems. Microsoft disclosed the issue on December 9, 2025, and it affects current Windows 11 and Windows Server releases.
Exploitation requires local access and low privileges. The attack complexity is high, which limits opportunistic exploitation. However, successful exploitation compromises confidentiality, integrity, and availability of the target system.
Critical Impact
A local, authenticated attacker who wins a race in the Brokering File System can obtain SYSTEM-level privileges on Windows 11 and Windows Server 2022/2025.
Affected Products
- Microsoft Windows 11 24H2
- Microsoft Windows 11 25H2
- Microsoft Windows Server 2022 23H2
- Microsoft Windows Server 2025
Discovery Timeline
- 2025-12-09 - CVE-2025-62569 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-62569
Vulnerability Analysis
The vulnerability resides in the Microsoft Brokering File System, a Windows component that mediates file access between processes and application containers. A use-after-free condition [CWE-416] occurs when the component references memory that has already been released. The freed allocation can be reclaimed by attacker-controlled data before the stale pointer is dereferenced.
Because the Brokering File System runs at higher privilege than the calling process, controlling the freed object allows an attacker to redirect execution into kernel or SYSTEM-level context. The CVSS vector reflects local attack surface with high attack complexity, indicating the issue involves a race condition or specific timing requirement to trigger the free-then-reuse sequence reliably.
Root Cause
The root cause is improper lifetime management of an object within the Brokering File System driver or service. Code paths release an object while another reference remains reachable, and a subsequent operation dereferences that stale pointer. The lack of synchronization between the free and the reuse enables an attacker with local code execution to spray the heap and reclaim the freed slot with a controlled structure.
Attack Vector
Exploitation requires the attacker to already hold a low-privileged account on the target host. The attacker triggers the vulnerable code path from user mode, then races the file system broker to allocate a substitute object at the freed address. On a successful race, the broker operates on the attacker-controlled memory and executes code or corrupts state in the security context of the broker. No user interaction is required. See the Microsoft CVE-2025-62569 Advisory for vendor details.
Detection Methods for CVE-2025-62569
Indicators of Compromise
- Unexpected child processes spawned by svchost.exe or Brokering File System service instances running as SYSTEM.
- Repeated crashes or WER (Windows Error Reporting) entries referencing the Brokering File System component after user-mode activity.
- Unusual token duplication or process integrity level changes from a low-privileged session to SYSTEM within a short window.
Detection Strategies
- Monitor for local processes performing high-frequency file broker requests followed by handle reuse patterns consistent with heap grooming.
- Alert on user-mode processes acquiring SYSTEM tokens without a corresponding legitimate service transition.
- Correlate kernel or service crashes in the Brokering File System with subsequent privilege changes on the same host.
Monitoring Recommendations
- Ingest Windows Security, System, and Sysmon logs into a centralized data lake to identify token elevation and process ancestry anomalies.
- Track patch state for Windows 11 24H2/25H2 and Windows Server 2022 23H2/2025 across the fleet to prioritize unpatched hosts.
- Baseline normal Brokering File System activity and alert on deviations, including repeated fault-and-recover cycles.
How to Mitigate CVE-2025-62569
Immediate Actions Required
- Apply the Microsoft security update referenced in the Microsoft CVE-2025-62569 Advisory to all affected Windows 11 and Windows Server systems.
- Prioritize multi-user hosts, terminal servers, and jump boxes where low-privileged users can execute code.
- Audit accounts with interactive or remote logon rights and remove unnecessary local access.
Patch Information
Microsoft has published the fix through the Microsoft Security Response Center. Refer to the Microsoft CVE-2025-62569 Advisory for the specific KB article, build numbers, and cumulative update packages applicable to each supported Windows version.
Workarounds
- No vendor-supplied workaround is documented. Applying the security update is the required remediation.
- Reduce exposure by restricting local logon rights and enforcing application allowlisting on shared systems until patches are deployed.
- Enable attack surface reduction rules and exploit protection settings to constrain unauthorized process behavior during the patch window.
# Verify patch state for CVE-2025-62569 on Windows hosts
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Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
