May 20, 2026 · Applied Cybernetics Group
CVE-2026-45498 — Microsoft Defender
Microsoft Defender Denial of Service Vulnerability
- Added to KEV
2026-05-20- Federal due date
2026-06-03- Vendor
- Microsoft
- Product
- Defender
- EPSS
- 89.6th percentile (score 0.047, as of
2026-06-08) - NVD CVSS v3.1
- 4 (MEDIUM)
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2026-45498
CISA short 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.
NVD description
Microsoft Defender Denial of Service Vulnerability