Detections
Analytics

Security Updates for Windows Defender (April 2026)

high Nessus Plugin ID 306740

Synopsis

An antimalware application installed on the remote host is affected by a privilege escalation vulnerability.

Description

The Antimalware Platform version of Microsoft Windows Defender installed on the remote Windows host is prior to 4.18.26030.3011. It is, therefore, affected by a privilege escalation vulnerability:

 - Insufficient granularity of access control in Microsoft Defender allows an authorized attacker to elevate privileges locally. (CVE-2026-33825)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update Microsoft Defender to platform version 4.18.26030.3011 or later.

See Also

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33825

Plugin Details

Severity: High

ID: 306740

File Name: smb_nt_ms26_apr_win_defender.nasl

Version: 1.1

Type: Local

Agent: windows

Published: 4/16/2026

Updated: 4/16/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-33825

CVSS v3

Risk Factor: High

Base Score: 7.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/a:microsoft:windows_defender

Required KB Items: installed_sw/Windows Defender

Patch Publication Date: 4/14/2026

Vulnerability Publication Date: 4/14/2026

Reference Information

CVE: CVE-2026-33825

IAVA: 2026-A-0352