CVE-2025-26648: Windows 10 1507 Privilege Escalation Flaw

CVE-2025-26648 Overview

CVE-2025-26648 is a local privilege escalation vulnerability in the Microsoft Windows Kernel. The flaw stems from sensitive data being stored in improperly locked memory, allowing an authorized attacker to elevate privileges on the affected host. Microsoft classifies the issue under [CWE-416] (Use After Free), indicating memory lifetime mismanagement in kernel-mode structures. The vulnerability affects a broad set of Windows client and server releases, including Windows 10, Windows 11, and Windows Server versions from 2008 through 2025. Microsoft published the advisory on April 8, 2025.

Critical Impact
A local, low-privileged attacker can elevate to SYSTEM on unpatched Windows hosts, achieving full confidentiality, integrity, and availability impact on the compromised endpoint.

Affected Products

Microsoft Windows 10 (1507, 1607, 1809, 21H2, 22H2)
Microsoft Windows 11 (22H2, 23H2, 24H2)
Microsoft Windows Server 2008, 2012, 2016, 2019, 2022, 2022 23H2, and 2025

Discovery Timeline

2025-04-08 - CVE-2025-26648 published to NVD
2025-04-08 - Microsoft releases security update via MSRC advisory
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-26648

Vulnerability Analysis

The vulnerability resides in the Windows Kernel, where sensitive data is stored in memory that is not properly locked against unauthorized access or premature release. According to Microsoft, the underlying weakness is a use-after-free condition ([CWE-416]). Kernel objects that hold privileged data can be referenced after the backing allocation has been released or repurposed, enabling an attacker holding a stale reference to read or manipulate sensitive kernel state.

Exploitation requires an authorized local user context. Successful abuse yields high impact across confidentiality, integrity, and availability, consistent with a kernel-mode elevation-of-privilege primitive that transitions a low-integrity process to SYSTEM.

Root Cause

The root cause is improper memory locking in the kernel path that handles sensitive data. The affected code fails to guarantee exclusive ownership of an object for the full duration of its use. When the allocation is freed or unlocked while another code path still holds a reference, the freed slot can be reclaimed by attacker-controlled data. Subsequent dereferences operate on attacker-influenced memory in kernel context.

Attack Vector

The attack vector is local. An attacker must already be able to execute code on the target with standard user privileges, for example through malware, a compromised service account, or an interactive session. The attacker triggers the vulnerable kernel code path, races the free operation, and reclaims the freed memory with a crafted payload to hijack kernel execution or corrupt privileged tokens. No user interaction is required, and the attack does not cross a security boundary at the network layer.

No public proof-of-concept exploit and no confirmed in-the-wild exploitation have been published for this CVE at the time of writing.

Detection Methods for CVE-2025-26648

Indicators of Compromise

Unexpected token duplication or SYSTEM-privileged child processes spawned from standard-user parents such as explorer.exe or unsigned user-mode binaries.
Kernel bugcheck events (BSOD) referencing pool corruption, BAD_POOL_HEADER, or KERNEL_MODE_HEAP_CORRUPTION on hosts running unpatched Windows builds.
Loading of unsigned or newly dropped drivers immediately prior to privilege changes on the endpoint.

Detection Strategies

Hunt for local processes that acquire SeDebugPrivilege or SYSTEM integrity level without a matching service or elevation event.
Correlate Sysmon Event ID 10 (process access) targeting lsass.exe or winlogon.exe with subsequent Event ID 1 process creations under NT AUTHORITY\SYSTEM.
Monitor Windows Event Log channel Microsoft-Windows-Kernel-General for anomalous object handle patterns and unexpected driver load events (Event ID 6 in Sysmon).

Monitoring Recommendations

Enable and forward kernel, security, and Sysmon logs to a centralized analytics pipeline for behavioral correlation.
Baseline privilege-change events per host and alert on deviations, especially token elevation from non-administrative sessions.
Track Windows patch state across the fleet and alert when hosts running affected builds miss the April 2025 cumulative update.

How to Mitigate CVE-2025-26648

Immediate Actions Required

Apply the April 2025 Microsoft security update referenced in the Microsoft Vulnerability Advisory CVE-2025-26648 to all affected Windows client and server systems.
Prioritize patching of multi-user hosts, jump servers, and endpoints where non-administrative users can execute code.
Audit local accounts and service accounts to reduce the population of users that could stage a local exploit.

Patch Information

Microsoft addressed CVE-2025-26648 in the security updates released on April 8, 2025. Refer to the Microsoft Vulnerability Advisory CVE-2025-26648 for the specific KB article that corresponds to each Windows build. Install the cumulative update through Windows Update, WSUS, Microsoft Update Catalog, or your enterprise patch management tool, and reboot affected systems to activate the kernel fix.

Workarounds

No official workaround is documented by Microsoft; patching is the supported remediation.
Where patching must be delayed, restrict local logon rights and application execution via AppLocker or Windows Defender Application Control to limit who can trigger the vulnerable kernel path.
Enforce least privilege and remove standard users from any group that permits driver installation or arbitrary code execution.

bash

# Verify installation of the April 2025 cumulative update on Windows
wmic qfe list brief /format:table

# PowerShell equivalent - list installed hotfixes sorted by install date
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object HotFixID,InstalledOn,Description