Detections
Analytics
Security Updates for Microsoft Malware Protection Engine (July 2026)
high Nessus Plugin ID 330603
Synopsis
The Microsoft Malware Protection Engine installation on the remote host is affected by multiple vulnerabilities.Description
The Microsoft Malware Protection Engine installation on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:- Integer underflow (wrap or wraparound) in Microsoft Defender allows an unauthorized attacker to execute code locally.
(CVE-2026-55011)
- Integer overflow or wraparound in Microsoft Defender allows an unauthorized attacker to execute code locally.
(CVE-2026-55012)
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Enable automatic updates to update the malware engine for the relevant antimalware applications. Refer to Knowledge Base Article 2510781 for information on how to verify that MMPE has been updated.See Also
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55011
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55012
Plugin Details
Severity: High
ID: 330603
File Name: smb_nt_ms26_jul_win_defender.nasl
Version: 1.1
Type: Local
Agent: windows
Family: Windows : Microsoft Bulletins
Published: 7/29/2026
Updated: 7/29/2026
Supported Sensors: Nessus Agent, Nessus
Risk Information
VPR
Risk Factor: Medium
Score: 6.9
Percentile: 96.93
CVSS v2
Risk Factor: High
Base Score: 7.2
Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS Score Source: CVE-2026-55011
CVSS v3
Risk Factor: High
Base Score: 7.8
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vulnerability Information
CPE: cpe:/a:microsoft:windows_defender, cpe:/o:microsoft:windows
Required KB Items: installed_sw/Windows Defender
Patch Publication Date: 7/14/2026
Vulnerability Publication Date: 7/14/2026
Reference Information
CVE: CVE-2026-55011, CVE-2026-55012