CISA KEV · Known exploitedHigh

CVE-2026-45498

Microsoft Microsoft Defender Antimalware Platform, defender antimalware platform

CVE-2026-45498 affects Microsoft Microsoft Defender Antimalware Platform, defender antimalware platform. Review the CVSS score, exploitation signals, affected versions, remediation status, and linked source material before making a change.

CVSS
7.5
EPSS
63.1%
99.1% percentile
CISA KEV
Listed
Published
2026.05.20
PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV
Exploit probability63.1%
Technical severityCVSS 7.5

Vulnerability overview

CVE-2026-45498 affects Microsoft Microsoft Defender Antimalware Platform, defender antimalware platform. Review the CVSS score, exploitation signals, affected versions, remediation status, and linked source material before making a change.

Affected product and versions

Product
Microsoft Microsoft Defender Antimalware Platform, defender antimalware platform
Affected versions
>= 4.0.0.0 < 4.18.26040.7
Fixed versions
4.18.26040.7

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Due date: 2026.06.03
  1. 1
    Identify

    Confirm that Microsoft Microsoft Defender Antimalware Platform, defender antimalware platform and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
CWE-400
KEV added
2026.05.20
Ransomware use
미확인
CVE-2026-45498 — Microsoft Microsoft Defender Antimalware Platform, defender antimalware platform | SECUFOCUS NOW