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Microsoft Security Response CenterCVE-2026-55011

Microsoft Defender Remote Code Execution Vulnerability

Integer underflow (wrap or wraparound) in Microsoft Defender allows an unauthorized attacker to execute code locally.

7.8CVSS out of 10Critical severity
Scope

What the vendor says is affected

  • Microsoft Malware Protection Engine

Versions the vendor lists as fixed

  • 1.1.26060.3008
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. Added to SecurityAlert

    We collected the advisory from the official source.

Vulnerabilities

CVEs named in this advisory