CVE-2026-45498

Microsoft Defender Denial of Service Vulnerability

CVSS 3.1 Medium 4.0Known exploited (CISA KEV)

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C

Description

Microsoft Defender Denial of Service Vulnerability

Key data

CVSS 3.1 Medium 4.0

Score published by microsoft in the CVE record.

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C

Attack vector: Local
The attacker needs local access to the system, or to trick a user into running something.
Attack complexity: Low
No special conditions are needed. The attack can be repeated at will.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Scope: Unchanged
The impact stays within the vulnerable component.
Confidentiality impact: None
No effect on the secrecy of data.
Integrity impact: None
No effect on the trustworthiness of data.
Availability impact: Low
Limited effect on availability.

Metric	Value	What it means
Attack vector	Local	The attacker needs local access to the system, or to trick a user into running something.
Attack complexity	Low	No special conditions are needed. The attack can be repeated at will.
Privileges required	None	No account or privileges are needed.
User interaction	None	No action from any user is needed.
Scope	Unchanged	The impact stays within the vulnerable component.
Confidentiality impact	None	No effect on the secrecy of data.
Integrity impact	None	No effect on the trustworthiness of data.
Availability impact	Low	Limited effect on availability.

CVSS is owned and managed by FIRST.Org, Inc. (FIRST) and is used by permission. Each CVSS score on this site is shown together with its vector string, as published in the CVE record by the source named next to it. Learn more at first.org/cvss.

EPSS

Exploit Prediction Scoring System by FIRST: an estimate of the probability that exploitation activity will be observed in the next 30 days.

Score: 0.63076 (63.1% probability)
Percentile: 99.2%
Scores of: Nov 10, 2026
Model: v2026.06.15

CISA Known Exploited Vulnerabilities

This CVE is listed in the CISA KEV catalog.

Name in the catalog: Microsoft Defender Denial of Service Vulnerability
Added to the catalog: May 20, 2026
Federal due date: Jun 3, 2026

CISA assessment as of May 21, 2026

Stakeholder-Specific Vulnerability Categorization (SSVC) decision points added by CISA.

Exploitation: Recorded by CISA as active
Automatable: no
Technical impact: partial

Weakness (CWE)

CWE catalog version 5.0.

CWE-400Uncontrolled Resource Consumption

Affected products

Products listed in the CVE record, as the CNA published them.

Microsoft Defender Antimalware Platform
- affected: 4.0.0.0 up to before 4.18.26040.7

References

Links listed in the CVE record. They lead to other sites, which CubePath does not control.

Microsoft Defender Denial of Service Vulnerability (msrc.microsoft.com)vendor-advisorypatch

Timeline

ID reservedMay 12, 2026
Added to CISA KEVMay 20, 2026
Record publishedMay 20, 2026
Record last updatedAug 10, 2026

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About CubePath

CubePath is a cloud provider with data centers in Europe and the United States. It offers VPS, bare metal servers and DDoS protection.

Cloud VPS DDoS protection

Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:10 UTC. Sources and licenses