---
id: CVE-2026-45498
title: Microsoft Defender Denial of Service Vulnerability
summary: Microsoft Defender Denial of Service Vulnerability
severity: medium
cvss: 4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-400
vendor: microsoft
product: defender_antimalware_platform
affected:
  - defender_antimalware_platform < 4.18.26040.7
patched:
  - defender_antimalware_platform 4.18.26040.7
published: '2026-05-20'
updated: '2026-07-23'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-45498'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45498'
    label: secure@microsoft.com
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45498
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - kev
  - in-the-wild
  - exploit-available
epss: 0.01267
epssPercentile: 0.6848
kev: true
kevDateAdded: '2026-05-20'
kevDueDate: '2026-06-03'
kevRansomware: false
exploited: true
zeroDay: true
ingestedAt: '2026-07-23T12:17:54.816Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/salihuahmad105-creator/Vulnerability-scanner'
  checkedAt: '2026-09-25T08:20:58.091Z'
exploitAvailable: true
---

## Overview

Microsoft Defender Denial of Service Vulnerability

## Affected

- `defender_antimalware_platform < 4.18.26040.7`

## Remediation

Upgrade past the affected range:

- `defender_antimalware_platform 4.18.26040.7`