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TI-2026-33268 Aliases CVE-2026-45498GHSA-8gp3-pghr-6wxp

Microsoft Defender Denial of Service Vulnerability

Priority CRITICAL 90Exploited in the wildCWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from Microsoft.

Summary

Microsoft Defender Denial of Service Vulnerability

Why it matters now

Exploitation Active In CISA KEV since 2026-05-20CISA due date 2026-06-03
EPSS 0.63076 99th percentileScored 2026-11-07
Fix Fixed Microsoft Defender Antimalware Platform (Microsoft): 4.18.26040.7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Active
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft Defender Antimalware Platform4.0.0.0 to before 4.18.26040.74.18.26040.7Patch availableCNA
  • Microsoft Defender Antimalware Platform VendorMicrosoft Affected 4.0.0.0 to before 4.18.26040.7 Fixed in 4.18.26040.7 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:defender_antimalware_platform:*:*:*:*:*:*:*:*before 4.18.26040.7VulnerableMicrosoft
  • cpe:2.3:a:microsoft:defender_antimalware_platform:*:*:*:*:*:*:*:* Versions before 4.18.26040.7 Vulnerable ·Microsoft

Remediation

  • Fix · CNA Microsoft Defender Antimalware Platform (Microsoft) Fixed in 4.18.26040.7

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Denial of Service
Exploited
Yes
Publicly disclosed
Yes
Exploitability
Exploitation Detected
ProductStatusPlan or fix
Microsoft Defender Antimalware PlatformFixed 4.18.26040.7 · Security Update

Timeline

  1. 2026-05-20 Added to CISA KEV
  2. 2026-10-02 Threatist record created from CVE-2026-45498
  3. 2026-10-03 Alias added: GHSA-8gp3-pghr-6wxp
  4. 2026-10-25 EPSS moved to the 99th percentile and above

References

Patch 1

Advisory 1

  • TI-2026-26195 Microsoft Defender Elevation of Privilege Vulnerability KEVCVSS 3.1HIGH 7.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences