Microsoft Defender for Linux
CVE-2026-21537 — Microsoft Defender for Endpoint Linux Extension Remote Code Execution Vulnerability
Executive Summary
Improper control of generation of code ('code injection') in Microsoft Defender for Linux allows an unauthorized attacker to execute code over an adjacent network.
Overview
8.8
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Adjacent_network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.7
EPSS Score
0.00532
probability of exploitation in the next 30 days
0.4181 percentile - updated 2026-07-25
View on FIRST.org
Affected Products
1 affected product
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft Defender for Endpoint for Linux | Release Notes (Security Update) |
Important | Remote Code Execution | Maybe |
Patches
1 patch
| Article | Type | Restart |
|---|---|---|
Release Notes |
Security Update | Maybe |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
Michal Kamensky with Microsoft
References
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