CVE-2026-45498 represents a denial of service vector affecting Microsoft Defender across multiple deployment configurations; exploitation requires local or proximate network access and results in service interruption rather than privilege escalation or data exfiltration. The vulnerability has been catalogued by CISA under Known Exploited Vulnerabilities as of current cycle, indicating active threat actor reconnaissance. Mitigation requires deployment of vendor security updates; organizations operating Windows infrastructure should prioritize patching cycles for Defender components to 1700 UTC deployment threshold or equivalent internal SLA.