Windows Defender < 4.18.26040.7 DoS (CVE-2026-45498)

high Nessus Plugin ID 316484

Synopsis

An antimalware application installed on the remote host is affected by a denial of service vulnerability.

Description

The Antimalware Platform version of Microsoft Windows Defender installed on the remote Windows host is prior to 4.18.26040.7. It is, therefore, affected by a denial of service vulnerability:

- Microsoft Defender Denial of Service Vulnerability. (CVE-2026-45498)

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 4.18.26040.7 or later.

See Also

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45498

Plugin Details

Severity: High

ID: 316484

File Name: smb_nt_ms26_may_win_defender_cve-2026-45498.nasl

Version: 1.1

Type: Local

Agent: windows

Published: 5/22/2026

Updated: 5/22/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.1

CVSS v2

Risk Factor: High

Base Score: 7.8

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

CVSS Score Source: CVE-2026-45498

CVSS v3

Risk Factor: High

Base Score: 7.5

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

Vulnerability Information

CPE: cpe:/a:microsoft:windows_defender

Required KB Items: installed_sw/Windows Defender

Patch Publication Date: 5/19/2026

Vulnerability Publication Date: 5/19/2026

CISA Known Exploited Vulnerability Due Dates: 6/4/2026

Reference Information

CVE: CVE-2026-45498