Unauthenticated adjacent-network code execution
Published Feb 10, 2026 · Updated Feb 10, 2026
Code injection in Microsoft Defender for Endpoint for Linux before 1.0.9.0 allows remote attackers to execute code over an adjacent network. Microsoft has not disclosed the vulnerable component or how adjacent-network input reaches code generation. Exploitation requires access from the same network subnet but no privileges or user interaction, and successful attacks compromise confidentiality, integrity, and availability.
Summary
What happened
Code injection in Microsoft Defender for Endpoint for Linux before 1.0.9.0 allows remote attackers to execute code over an adjacent network. Microsoft has not disclosed the vulnerable component or how adjacent-network input reaches code generation. Exploitation requires access from the same network subnet but no privileges or user interaction, and successful attacks compromise confidentiality, integrity, and availability.
The record
- CVE
- CVE-2026-21537
- Published
- Feb 10, 2026
- Updated
- Feb 10, 2026
- Vendor
- Microsoft
- Product
- Microsoft Defender for Endpoint for Linux
- Classifications
- CWE-94, T1210
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 10, 2026CVE publishedPublication date reported by the CVE source.
- Feb 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=101.0.0 <1.0.9.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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