CVE-2026-45584

HIGH

Microsoft Defender Remote Code Execution Vulnerability

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-45584. PoCs published by 96613686.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-45584, a heap out-of-bounds write vulnerability in Microsoft Defender's mpengine.dll. The exploit leverages a crafted ZIP file with a near-maximum-length archive path to trigger a crash during scanning, demonstrating the vulnerability.

Description

Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.

Exploits (1)

github WORKING POC
by 96613686 · poc
https://github.com/96613686/CVE-2026-45584

This repository contains a functional exploit for CVE-2026-45584, a heap out-of-bounds write vulnerability in Microsoft Defender's mpengine.dll. The exploit leverages a crafted ZIP file with a near-maximum-length archive path to trigger a crash during scanning, demonstrating the vulnerability.

Classification
Working Poc 95%
Attack Type
Dos
Complexity
Moderate
Reliability
Reliable
Target: Microsoft Defender (mpengine.dll) Platform 4.18.26030.3011-0
No auth needed
Prerequisites: Microsoft Defender enabled with real-time protection · Crafted ZIP file with long path
devstral-2 · analyzed May 22, 2026 Full analysis →

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory patch
Microsoft Defender Remote Code Execution Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45584

Scores

CVSS v3 8.1
EPSS 0.0004
EPSS Percentile 11.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-122
Status published
Products (2)
microsoft/malware_protection_engine 1.1.26030.3008 - 1.1.26040.8
Microsoft/Microsoft Malware Protection Engine -
Published May 20, 2026
Tracked Since May 20, 2026