Vulnerability

CERT-In Vulnerability Note CIVN-2026-0453
Privilege Escalation Vulnerability in Microsoft Defender

Original Issue Date:September 10, 2026

Severity Rating: HIGH

Software Affected

Microsoft Malware Protection Engine

Overview

A vulnerability has been reported in Microsoft Malware Protection Engine which could allow an attacker with low-level local access to elevate privileges on an affected system.

Target Audience:
Organizations and individuals using Microsoft Malware Protection Engine

Risk Assessment:
High risk of privilege escalation and potential compromise of the affected system.

Impact Assessment:
Potential for unauthorized access of data and compromise of the affected system.

Description

Microsoft Malware Protection Engine (MMPE) is a core security component used by Microsoft security products, including Microsoft Defender Antivirus, to detect, analyze, and help remove malware and other potentially unwanted or malicious software from Windows systems.

This vulnerability exists due to improper access control/privilege management within the Microsoft Malware Protection Engine.

Successful exploitation of this vulnerability could allow an attacker with low-level local access to elevate privileges on an affected system, potentially resulting in unauthorized access to protected resources and the complete compromise of the affected system.

Solution

Apply appropriate security updates as mentioned in
https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-69414

Vendor Information

Microsoft
https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-69414

References

https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-69414

CVE Name
CVE-2026-69414

Disclaimer

The information provided herein is on "as is" basis, without warranty of any kind.

Contact Information

Email: info@cert-in.org.in
Phone: +91-11-22902657

Postal address

Indian Computer Emergency Response Team (CERT-In)
Ministry of Electronics and Information Technology
Government of India
Electronics Niketan
6, CGO Complex, Lodhi Road,
New Delhi - 110 003
India