CVE-2026-45498Vulnerability
Microsoft Defender Denial of Service Vulnerability
Exploited in the wildCISA added it to its Known Exploited Vulnerabilities list on .
Reported by 1 independent source · first reported by The Hacker News · last reported
Last reported 1 month ago
CISA KEVAdded 20 May 2026
Fix due 3 Jun 2026
Used by ransomware: not knownCISA KEV catalogue
Fix due 3 Jun 2026
Used by ransomware: not knownCISA KEV catalogue
EPSS1.3%
higher than 69% of CVEsFIRST EPSS, as of 23 Oct 2026
higher than 69% of CVEsFIRST EPSS, as of 23 Oct 2026
What the reports say
1 report, newest first · the exact sentence from each-
Researcher Drops BigDiskBuster Zero-Day PoC That Blocks Microsoft Defender Updates“Microsoft patched it in May as CVE-2026-45498 in Antimalware Platform version 4.18.26040.7.”
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