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TI-2026-33333 Aliases CVE-2026-45584GHSA-f7rp-9ghh-f4gm

Microsoft Defender Remote Code Execution Vulnerability

Priority LOW 39CWE-122Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
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

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00852 58th percentileScored 2026-11-07
Fix Fixed Microsoft Malware Protection Engine (Microsoft): 1.1.26040.8

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

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft Malware Protection Engine1.1.0.0 to before 1.1.26040.81.1.26040.8Patch availableCNA
  • Microsoft Malware Protection Engine VendorMicrosoft Affected 1.1.0.0 to before 1.1.26040.8 Fixed in 1.1.26040.8 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:*1.1.26030.3008 to before 1.1.26040.8VulnerableMicrosoft
  • cpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:* Versions 1.1.26030.3008 to before 1.1.26040.8 Vulnerable ·Microsoft

Remediation

  • Fix · CNA Microsoft Malware Protection Engine (Microsoft) Fixed in 1.1.26040.8

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Remote Code Execution
Exploited
No
Publicly disclosed
No
Exploitability
—
ProductStatusPlan or fix
Microsoft Malware Protection EngineFixed 1.1.26040.8 · Security Update

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45584
  2. 2026-10-03 Alias added: GHSA-f7rp-9ghh-f4gm

References

Patch 1

  • 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