Microsoft Defender Denial of Service Vulnerability
Description
Microsoft Defender contains an unspecified vulnerability that allows for denial of service.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
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Details
- Vendor
- Microsoft
- Product
- Microsoft Defender
- CVE
- CVE-2026-45498
- Affected versions
- Microsoft Defender Antimalware Platform 4: from 4.0.0.0 to 4.18.26040.7 (excluded) — fixed in 4.18.26040.7 (from the advisory and NVD; check the exact builds in the official advisory)
- CVSS score
- 4
- Actively exploited
- Yes, listed in the CISA Known Exploited Vulnerabilities catalog
- CISA due date
- June 3, 2026 (deadline for US federal agencies: a good benchmark for you too)
- Source
- CISA KEV – original advisory
- Published
- May 20, 2026
The description and the recommended action are quoted from the public advisory; severity, exploitation status and affected versions are compiled automatically from public sources and may contain errors. The vendor's original advisory prevails: check it before taking action. This information is provided without warranty and does not replace a professional assessment.