Defender 4 vulnerabilities
2 advisories affect Microsoft Defender 4, 2 already exploited by attackers. Latest: May 20, 2026.
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| Vulnerability | Severity | Affected versions |
|---|---|---|
| Microsoft Defender Denial of Service Vulnerability CVE-2026-45498 · May 20, 2026 | Medium 4 Exploited | from 4.0.0.0 to 4.18.26040.7 (excluded) Fixed in 4.18.26040.7 |
| Microsoft Defender Insufficient Granularity of Access Control Vulnerability CVE-2026-33825 · April 22, 2026 | High 7.8 Exploited | from 4.0.0.0 to 4.18.26030.3011 (excluded) Fixed in 4.18.26030.3011 |
Affected versions are compiled automatically from vendor advisories and NVD and may contain errors. Where no fixed version is shown, you will find it in the official advisory linked from every page: check it there before updating.