Resource exhaustion in Microsoft Defender_antimalware_platform

CVE-2026-45498

Microsoft Defender Denial of Service Vulnerability

Vulnerability class: DoS (Denial of Service)

EPSS: 0.041 (88.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Affected products

Weakness classification (CWE)

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: .

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.

References

Frequently asked questions

What is CVE-2026-45498?
CVE-2026-45498 is a medium-severity vulnerability in Microsoft Defender_antimalware_platform, classified under Uncontrolled Resource Consumption. CVSS score: 4.0/10. Published 2026-05-20.
How severe is CVE-2026-45498?
Medium severity. CVSS v3 base score is 4.0 out of 10.
Is CVE-2026-45498 known to be exploited?
Yes. CVE-2026-45498 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-05-20), indicating it is being actively exploited.