Resource exhaustion in Microsoft Defender Antimalware Platform
CVE-2026-45498
Microsoft Defender Denial of Service Vulnerability
Vulnerability class: DoS (Denial of Service)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.013 (69.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.631 · newest: 0.013 · change: -0.618
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.
Public proof-of-concept exploits
References
- Microsoft Defender Denial of Service Vulnerability (vendor-advisory, patch, Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource, Third Party Advisory)
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. 1 public proof-of-concept repositories are indexed.