TI-2026-39719 Aliases CVE-2026-55012 GHSA-9r74-q979-v6gq

Microsoft Defender Remote Code Execution Vulnerability

LOW 36CWE-122Published 2026-07-14 · Updated 2026-11-01

Key facts

Attack vector: Local
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from Microsoft.

Summary

Integer overflow or wraparound in Microsoft Defender allows an unauthorized attacker to execute code locally.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00466 40th percentileScored 2026-11-07

Fix Fixed Microsoft Malware Protection Engine (Microsoft): 1.1.26060.3008

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Microsoft	Microsoft Malware Protection Engine	1.1.0.0 to before 1.1.26060.3008	1.1.26060.3008	Patch available	CNA

Microsoft Malware Protection Engine VendorMicrosoft Affected 1.1.0.0 to before 1.1.26060.3008 Fixed in 1.1.26060.3008 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:microsoft:malware_protection_engine::::::::	before 1.1.26060.3008	Vulnerable	Microsoft

cpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:* Versions before 1.1.26060.3008 Vulnerable ·Microsoft

Remediation

Fix · CNA Microsoft Malware Protection Engine (Microsoft) Fixed in 1.1.26060.3008

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact: Remote Code Execution
Exploited: No
Publicly disclosed: No
Exploitability: Exploitation Less Likely

Product	Status	Plan or fix
Microsoft Malware Protection Engine	Fixed	1.1.26060.3008 · Security Update

Timeline

2026-10-02 Threatist record created from CVE-2026-55012
2026-10-03 Alias added: GHSA-9r74-q979-v6gq

References

Patch 1

Microsoft Defender Remote Code Execution Vulnerability

TI-2026-29727 Microsoft Defender Elevation of Privilege Vulnerability KEVCVSS 3.1HIGH 7.8
TI-2017-06074 Out-of-bounds write in Microsoft Malware Protection Engine KEVCVSS 3.1HIGH 7.8
TI-2017-00265 Memory corruption in Microsoft Malware Protection Engine CVSS 3.0HIGH 7.8
TI-2026-48742 Microsoft Defender Elevation of Privilege Vulnerability CVSS 3.1HIGH 7.8
TI-2026-37344 Microsoft Defender Elevation of Privilege Vulnerability CVSS 3.1HIGH 7.8
TI-2017-06072 Memory corruption in Microsoft Malware Protection Engine CVSS 3.0HIGH 7.8

See all 30 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences