CVE-2026-45498

Microsoft Defender Antimalware Platform

Published 20 May 2026 · updated 23 Jul 2026 · Analyzed

7.5 High · CVSS 3.1, NVD

Exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on 20 May 2026, with a remediation deadline of 3 Jun 2026 for US federal agencies.

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

Description

Microsoft Defender Denial of Service Vulnerability

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45498 · Vendor Advisory
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45498 · Third Party Advisory, US Government Resource