CVE-2026-45498Known exploitation

Local service interruption via resource exhaustion

Published May 20, 2026 · Updated May 20, 2026

Uncontrolled resource consumption in Microsoft Defender Antimalware Platform before 4.18.26040.7 allows local users to interrupt antivirus service. Microsoft has not disclosed the input, code path, or resource whose unbounded consumption exhausts the antimalware platform. Exploitation requires local access but no privileges or user interaction; the published impact is limited availability loss, and CISA reports active exploitation.

CVSS severity4.0
Medium
EPSS probability63.08%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Microsoft Defender Antimalware Platform before 4.18.26040.7 allows local users to interrupt antivirus service. Microsoft has not disclosed the input, code path, or resource whose unbounded consumption exhausts the antimalware platform. Exploitation requires local access but no privileges or user interaction; the published impact is limited availability loss, and CISA reports active exploitation.

The record

CVE
CVE-2026-45498
Published
May 20, 2026
Updated
May 20, 2026
Vendor
Microsoft
Product
Microsoft Defender Antivirus Antimalware Platform
Classifications
CWE-400, T1562.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 20, 2026CVE publishedPublication date reported by the CVE source.
  2. May 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=-

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Defender Antivirus Antimalware Platformversion=-

Published CVSS scores

4.0Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1562.001Impair Defenses: Disable or Modify Tools

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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