CVE-2026-25165: Windows Performance Counters Privilege Escalation

CVE-2026-25165 Overview

A null pointer dereference vulnerability exists in Windows Performance Counters that allows an authorized attacker to elevate privileges locally. This memory corruption flaw occurs when the Windows Performance Counters component improperly handles memory references, leading to a condition where a null pointer is dereferenced during execution. An attacker with local access and valid credentials could exploit this vulnerability to gain elevated privileges on the affected system.

Critical Impact

Successful exploitation allows local privilege escalation, potentially enabling an attacker with low-level access to gain SYSTEM-level privileges on vulnerable Windows systems.

Affected Products

• Windows Performance Counters component
• Microsoft Windows operating systems with Performance Counters enabled

Discovery Timeline

• 2026-03-10 - CVE-2026-25165 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2026-25165

Vulnerability Analysis

This vulnerability is classified as CWE-476 (NULL Pointer Dereference), a memory corruption vulnerability that occurs when an application attempts to use a pointer that has a NULL value, typically resulting in a crash or exploitable condition. In the context of Windows Performance Counters, this flaw can be leveraged beyond a simple denial of service to achieve privilege escalation.

The Windows Performance Counters subsystem is responsible for collecting and exposing system performance metrics. When handling certain operations, the component fails to properly validate memory references before use, creating a condition where an attacker with local access can manipulate the execution flow to elevate their privileges.

Root Cause

The root cause of this vulnerability lies in insufficient validation of pointer values within the Windows Performance Counters component. The code path fails to verify that a pointer is valid (non-NULL) before dereferencing it. This missing null check allows an attacker to craft specific inputs or conditions that trigger the dereference of an uninitialized or explicitly nullified pointer, which can then be exploited to redirect execution or corrupt memory in a controlled manner.

Attack Vector

This vulnerability requires local access to the target system and authenticated access with low privileges. The attacker must execute a specially crafted application or trigger specific conditions within the Performance Counters subsystem to exploit the null pointer dereference.

The exploitation mechanism involves manipulating the state of the Performance Counters component to force a null pointer condition. When the vulnerable code path is reached, the attacker can leverage the resulting memory corruption to escalate privileges from a low-privileged user account to potentially SYSTEM-level access.

For detailed technical information about this vulnerability, refer to the Microsoft Vulnerability Advisory.

Detection Methods for CVE-2026-25165

Indicators of Compromise

• Unexpected crashes or restarts of Performance Counter-related services
• Suspicious local processes attempting to interact with Performance Counter APIs with unusual parameters
• Evidence of privilege escalation activities following Performance Counter service anomalies
• Windows Event Log entries indicating application crashes in Performance Counter components

Detection Strategies

• Monitor for suspicious local process activity targeting Windows Performance Counter services
• Implement application whitelisting to prevent unauthorized executables from running
• Deploy endpoint detection and response (EDR) solutions capable of detecting privilege escalation attempts
• Enable and review Windows Security Event logs for privilege escalation indicators (Event IDs 4672, 4673)

Monitoring Recommendations

• Configure audit policies to log access to Performance Counter registry keys and APIs
• Establish baseline behavior for Performance Counter service operations and alert on deviations
• Monitor for unexpected SYSTEM-level process spawning from lower-privileged user contexts
• Implement real-time alerting for crash events in Windows performance monitoring components

How to Mitigate CVE-2026-25165

Immediate Actions Required

• Apply the latest Microsoft security updates addressing CVE-2026-25165 as soon as available
• Restrict local access to systems where possible, limiting the attack surface
• Audit user accounts with local access privileges and remove unnecessary permissions
• Enable enhanced monitoring on critical systems until patches are deployed

Patch Information

Microsoft has released a security update to address this vulnerability. Organizations should consult the Microsoft Vulnerability Advisory for specific patch information and apply the appropriate updates through Windows Update or Microsoft Update Catalog.

Workarounds

• Limit local access to affected systems to trusted administrators only
• Implement the principle of least privilege for all user accounts
• Consider restricting access to Performance Counter APIs via Group Policy if operationally feasible
• Deploy application control solutions to prevent execution of untrusted code

# Review current Performance Counter configuration
# Check Windows Event Viewer for related crashes
wevtutil qe Application /q:"*[System[Provider[@Name='Application Error']]]" /c:50 /f:text

# Verify patch status using PowerShell
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 10