CVE-2025-53155: Windows 10 1507 Privilege Escalation Flaw

CVE-2025-53155 Overview

CVE-2025-53155 is a heap-based buffer overflow vulnerability in Windows Hyper-V. An authenticated local attacker can trigger the flaw to elevate privileges on the host system. Microsoft disclosed the issue on August 12, 2025, and it affects a broad range of Windows client and server versions that ship Hyper-V, from Windows 10 1507 through Windows Server 2025.

The weakness is classified as CWE-122 (Heap-based Buffer Overflow). Successful exploitation can compromise the confidentiality, integrity, and availability of the affected host.

Critical Impact
A low-privileged attacker with local access can escalate to higher privileges on the Hyper-V host, potentially breaking guest-to-host isolation boundaries.

Affected Products

Microsoft Windows 10 (1507, 1607, 1809, 21H2, 22H2)
Microsoft Windows 11 (22H2, 23H2, 24H2)
Microsoft Windows Server 2012, 2016, 2019, 2022, 2022 23H2, and 2025

Discovery Timeline

2025-08-12 - CVE-2025-53155 published to NVD
2025-08-12 - Microsoft releases security advisory and patch
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-53155

Vulnerability Analysis

The vulnerability resides within the Windows Hyper-V virtualization stack. Hyper-V mediates communication between guest virtual machines and the host through virtualization service providers and worker processes. A heap-based buffer overflow occurs when Hyper-V processes attacker-controlled data without proper bounds validation. This allows adjacent heap metadata or objects to be overwritten during allocation or copy operations.

Because Hyper-V components run with elevated privileges on the host, corrupting heap structures can be leveraged to hijack control flow or manipulate privileged objects. The result is local privilege elevation with high impact to system confidentiality, integrity, and availability.

Root Cause

The root cause is improper bounds checking on a length or size field before writing to a heap-allocated buffer inside a Hyper-V kernel-mode or system-level component. When the input size exceeds the allocated region, adjacent heap memory is overwritten. Microsoft has not publicly disclosed the specific function or component involved.

Attack Vector

Exploitation requires local access and low-privileged authentication on the affected host. The attacker interacts with a Hyper-V interface reachable from a user-mode or guest context. By supplying crafted input to the vulnerable code path, the attacker triggers the heap overflow. Successful exploitation yields code execution or privilege elevation in the security context of the vulnerable Hyper-V component.

No public proof-of-concept or in-the-wild exploitation has been reported. See the Microsoft CVE-2025-53155 Advisory for vendor technical details.

Detection Methods for CVE-2025-53155

Indicators of Compromise

Unexpected crashes or bug checks referencing Hyper-V components such as vmms.exe, vmwp.exe, hvix64.exe, or hvax64.exe.
Creation of new privileged accounts or services on Hyper-V hosts shortly after suspicious guest activity.
Anomalous child processes spawned by Hyper-V worker or management processes.

Detection Strategies

Monitor Windows Event Logs for Hyper-V-Worker and Hyper-V-Hypervisor channel errors, kernel crashes, and unexpected VM worker process termination.
Alert on privilege escalation patterns such as token manipulation or new SYSTEM-context processes originating from user sessions on Hyper-V hosts.
Track patch state of Hyper-V roles across the environment and flag hosts missing the August 2025 security update.

Monitoring Recommendations

Ingest Sysmon and Windows Security logs from all Hyper-V hosts into a centralized SIEM for correlation.
Baseline normal behavior for Hyper-V worker processes and alert on deviations such as unexpected memory access patterns or crashes.
Review guest-to-host integration component activity for abnormal call rates or malformed requests.

How to Mitigate CVE-2025-53155

Immediate Actions Required

Apply the August 2025 Microsoft security update to all Hyper-V hosts running the affected Windows client or server versions.
Inventory all systems with the Hyper-V role enabled and prioritize patching for internet-adjacent or multi-tenant hosts.
Restrict local logon and Hyper-V administration privileges to a minimal set of trusted accounts.

Patch Information

Microsoft released fixes as part of the August 2025 Patch Tuesday cycle. Refer to the Microsoft CVE-2025-53155 Advisory for the exact KB article and build numbers for each affected Windows version. Apply the update through Windows Update, WSUS, or your preferred patch management tool.

Workarounds

If patching is not immediately possible, restrict who can create or run virtual machines on affected hosts to reduce the attacker population.
Disable the Hyper-V role on systems where it is not required until updates can be deployed.
Enforce least-privilege access to Hyper-V management interfaces and audit membership of the Hyper-V Administrators group.

bash

# Verify Hyper-V role status and patch level on Windows Server
Get-WindowsFeature -Name Hyper-V
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 10

# Optional: remove the Hyper-V role if not required
Uninstall-WindowsFeature -Name Hyper-V -Restart