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Microsoft Security Response CenterCVE-2026-45584

Microsoft Defender Remote Code Execution Vulnerability

Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.

Read the vendor bulletin Get alerts for Microsoft Malware Protection Engine
8.1CVSS out of 10Critical severity
Scope

What the vendor says is affected

  • Microsoft Malware Protection Engine

Versions the vendor lists as fixed

  • 1.1.26040.8
Next step

What the vendor recommends

Release Notes

Review the complete instructions on the vendor's site
Timeline

When this advisory changed

  1. Published by Microsoft Security Response Center

    The publication date reported by the vendor.

  2. Updated by Microsoft Security Response Center

    The vendor changed the advisory after it was first published.

  3. Added to SecurityAlert

    We collected the advisory from the official source.

Vulnerabilities

CVEs named in this advisory

CVE-2026-45584View CVSS, KEV, EPSS, and threat context
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