CVE-2026-25175: Windows NTFS Privilege Escalation Flaw

CVE-2026-25175 Overview

CVE-2026-25175 is an out-of-bounds read vulnerability in Windows NTFS that allows an authorized attacker to elevate privileges locally. This memory corruption flaw (CWE-125) enables a local attacker with low privileges to read beyond the boundaries of allocated memory buffers in the NTFS file system driver, potentially leading to privilege escalation on affected Windows systems.

Critical Impact

Local privilege escalation through NTFS out-of-bounds read could allow attackers to gain elevated system privileges, compromising confidentiality, integrity, and availability of the affected system.

Affected Products

• Windows NTFS File System Driver
• Windows Operating Systems with NTFS support

Discovery Timeline

• 2026-03-10 - CVE-2026-25175 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2026-25175

Vulnerability Analysis

This vulnerability stems from an out-of-bounds read condition in the Windows NTFS file system driver. When processing certain file system operations, the NTFS driver fails to properly validate buffer boundaries, allowing read operations to access memory outside the intended buffer allocation. An attacker who has already gained local access to the system with low-level privileges can exploit this flaw to read sensitive kernel memory, potentially disclosing information that enables privilege escalation to SYSTEM-level access.

The local attack vector requires the attacker to have authenticated access to the target system. Once authenticated, exploitation does not require any user interaction, making it particularly dangerous in multi-user environments or systems where untrusted users have limited access.

Root Cause

The root cause of CVE-2026-25175 is improper bounds checking in the NTFS file system driver when handling specific file system structures. The driver fails to validate that read operations stay within the boundaries of allocated memory buffers, leading to an out-of-bounds read condition (CWE-125). This allows an attacker to access adjacent memory regions that may contain sensitive kernel data or security tokens.

Attack Vector

The attack is executed locally by an authenticated user with low privileges. The attacker must be able to execute code on the target system to trigger the vulnerable code path in the NTFS driver. By crafting specific file system operations or malformed NTFS structures, the attacker can cause the driver to read beyond buffer boundaries, potentially leaking kernel memory contents that facilitate privilege escalation.

The vulnerability requires local access to exploit, meaning remote exploitation is not directly possible without first gaining a foothold on the target system through other means.

Detection Methods for CVE-2026-25175

Indicators of Compromise

• Unusual file system operations or NTFS-related system calls from low-privileged processes
• Unexpected kernel memory access patterns or anomalous NTFS driver behavior
• Processes attempting privilege escalation after performing file system operations
• Crash dumps or blue screens related to ntfs.sys driver memory access violations

Detection Strategies

• Monitor for suspicious processes attempting to access NTFS structures in abnormal ways
• Implement endpoint detection rules to identify privilege escalation attempts following file system operations
• Deploy behavioral analysis to detect processes that gain elevated privileges unexpectedly
• Enable Windows Event Logging for Security events related to privilege changes

Monitoring Recommendations

• Enable advanced audit policies for file system access and privilege use
• Configure SentinelOne agents to monitor for kernel-mode memory access anomalies
• Review security event logs for Event ID 4672 (Special Privileges Assigned) correlated with file system activity
• Implement real-time alerting for any process elevation patterns that deviate from baseline behavior

How to Mitigate CVE-2026-25175

Immediate Actions Required

• Apply Microsoft security updates addressing CVE-2026-25175 as soon as they become available
• Restrict local access to systems to only trusted and authorized users
• Implement the principle of least privilege to minimize the impact of potential exploitation
• Monitor systems for signs of exploitation attempts using endpoint detection tools

Patch Information

Microsoft has released a security advisory for this vulnerability. Organizations should consult the Microsoft CVE-2026-25175 Advisory for official patch information and apply the relevant Windows security updates through Windows Update, WSUS, or Microsoft Update Catalog.

Workarounds

• Limit local user access to systems that process sensitive data
• Implement application control policies to prevent unauthorized code execution
• Use SentinelOne's behavioral AI to detect and block privilege escalation attempts
• Consider network segmentation to limit lateral movement if exploitation occurs
• Enable Windows Defender Credential Guard where supported to protect authentication credentials

# Verify Windows security update status
wmic qfe list brief /format:table | findstr "KB"

# Check for pending updates via PowerShell
Get-WindowsUpdate -Verbose