CVE-2026-45498 (GCVE-0-2026-45498)

Vulnerability from cvelistv5 – Published: 2026-05-20 13:09 – Updated: 2026-08-10 15:13
VLAI CISA Previdian
Title
Microsoft Defender Denial of Service Vulnerability
Summary
Microsoft Defender Denial of Service Vulnerability
SSVC
Exploitation: active Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-21 03:55 UTC
CWE
  • CWE-400 - Uncontrolled Resource Consumption
References
Impacted products
Vendor Product Version
Microsoft Microsoft Defender Antimalware Platform Affected: 4.0.0.0 , < 4.18.26040.7 (custom)
    cpe:2.3:a:microsoft:microsoft_defender:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-05-19 14:00
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant

Vulnerability ID: CVE-2026-45498

Status: Confirmed

Status Updated: 2026-05-20 02:00 CEST

Exploited: Yes


Timestamps
First Seen: 2026-05-20
Asserted: 2026-05-20

Scope
Notes: Microsoft Defender Denial of Service Vulnerability | Affected: Microsoft / Defender | Description: Microsoft Defender contains an unspecified vulnerability that allows for denial of service. | 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 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-45498 ; https://nvd.nist.gov/vuln/detail/CVE-2026-45498

Evidence

Type: Vendor Report

Signal: Successful Exploitation

Confidence: 80%

Source: cisa-kev


Details
Cwes
Feed CISA Known Exploited Vulnerabilities Catalog
Product Defender
Due Date 2026-06-03
Date Added 2026-05-20
Vendorproject Microsoft
Vulnerabilityname Microsoft Defender Denial of Service Vulnerability
Knownransomwarecampaignuse Unknown

References

Created: 2026-10-02 08:09 CEST | Updated: 2026-10-02 08:09 CEST
Previdian
Known Exploited Vulnerability - GCVE BCP-07 Compliant

Vulnerability ID: CVE-2026-45498

Status: Confirmed

Status Updated: 2026-06-01 15:29 CEST

Exploited: Yes


Timestamps
First Seen: 2026-06-01
Asserted: 2026-06-01

Scope
Notes: Microsoft Defender Denial of Service Vulnerability | Affected: Microsoft / Microsoft Defender Antimalware Platform | CVSS: 4.0 (MEDIUM) | EPSS: 0.01267 | Used in malware: unknown | Listed 1 day ahead of CISA KEV | Not yet in CISA KEV: False

Evidence

Type: Public Report

Signal: Successful Exploitation

Confidence: 70%

Source: previdian


Details
Feed Previdian (previdian.com)
Title Microsoft Defender Denial of Service Vulnerability
Cve Id CVE-2026-45498
Vendor Microsoft
Ghsa Id None
Product Microsoft Defender Antimalware Platform
Added Date 2026-06-01T13:29:26.865Z
Cvss Score 4.0
Epss Score 0.01267
Previous Ids
Cvss Severity MEDIUM
Virtual Patch False
Cvss Estimated False
Epss Percentile 0.68692
Used In Malware unknown
Vulnerability Id CVE-2026-45498
Ahead Of Cisa Kev
{
  "count": 1,
  "unit": "day"
}
Not Yet In Cisa Kev False

References

Created: 2026-10-02 09:09 CEST | Updated: 2026-10-02 09:09 CEST
Show details on NVD website

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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
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