Microsoft Defender Denial of Service Vulnerability

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. May 20, 2026 · Catalog

   Detected

   Microsoft Defender contains an unspecified vulnerability that allows for denial of service.

2. May 20, 2026 · CISA KEV

   Known exploited

   Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

3. Jun 3, 2026 · CISA KEV

   Remediation due

   Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

4. Jul 23, 2026 · Catalog

   Updated

   Microsoft Defender contains an unspecified vulnerability that allows for denial of service.

Affected

• cpe microsoft/defender antimalware platformversion unspecified
• vendor Microsoft Defenderversion unspecified

Sources

• CISA KEVConfirmed exploitationCVE-2026-45498

  Microsoft Defender contains an unspecified vulnerability that allows for denial of service.

  cisa.gov
• CVE.orgVulnerability recordCVE-2026-45498

  Official CVE identifier

  cve.org
• FIRST EPSSExploitation probabilityCVE-2026-45498

  30-day exploitation probability 1.3%

  first.org
• NIST NVDVulnerability recordCVE-2026-45498

  Microsoft Defender Denial of Service Vulnerability

  nvd.nist.gov

References

• CISA note · msrc.microsoft.com
• Vendor Advisory · msrc.microsoft.com
• CISA note · nvd.nist.gov
• Third Party Advisory · cisa.gov