CVE-2026-45584: Microsoft Defender Remote Code Execution Vulnerability
Published May 19, 2026
·Updated
Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.
Other sources
Microsoft Defender Remote Code Execution Vulnerability
— Microsoft
Affected Software
3 affected componentsFixes available
Microsoft Malware Protection Engine
Microsoft Malware Protection Engine>=1.1.26030.3008<1.1.26040.8
Microsoft Malware Protection Engine<1.1.26040.8
1.1.26040.8
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.1.26040.8
Event History
May 19, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
May 20, 2026
CVE Published
via MITRE·01:09 PM
Data Sourced
via MITRE·01:09 PM
DescriptionSeverity
Data Sourced
via NVD·01:16 PM
DescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-45584?
CVE-2026-45584 has a severity rating of high with a score of 8.1.
2
How do I fix CVE-2026-45584?
To fix CVE-2026-45584, ensure that Microsoft Defender is updated to the latest version provided by Microsoft.
3
What type of vulnerability is CVE-2026-45584?
CVE-2026-45584 is a heap-based buffer overflow vulnerability.
4
What systems are affected by CVE-2026-45584?
CVE-2026-45584 affects the Microsoft Malware Protection Engine.
5
What can an attacker do with CVE-2026-45584?
An attacker can exploit CVE-2026-45584 to execute arbitrary code remotely over a network.