CVE-2026-45498 — Microsoft Defender Denial of Service Vulnerability
CVE-2026-45498: Microsoft Defender Denial of Service Vulnerability
CISA Known Exploited Vulnerability (KEV)
| Vendor / project | Microsoft |
| Product | Defender |
| Date added | 2026-05-20 |
| Due date | 2026-06-03 |
| Ransomware campaign use | Unknown |
Description
Microsoft Defender contains an unspecified vulnerability that allows for denial of service.
Required action (CISA)
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Notes
https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-45498 ; https://nvd.nist.gov/vuln/detail/CVE-2026-45498
References
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45498
- KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog