Defender for Endpoint and Antivirus
CVE-2026-21537: Microsoft Defender for Endpoint Linux Extension Remote Code Execution Vulnerability
Improper control of generation of code ('code injection') in Microsoft Defender for Linux allows an unauthorized attacker to execute code over an adjacent network.
Published
ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityHIGHCVSS 3.1 8.8
EPSS0.53%Chance of exploitation in 30 days
Public exploitNot tracked
FixAvailable
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| Microsoft Defender for Endpoint for Linux 101.0 | 1.0.9.0 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
Improper control of generation of code ('code injection') in Microsoft Defender for Linux allows an unauthorized attacker to execute code over an adjacent network.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 11 Oct 2026.