What is CVE-2026-21537?

CVE-2026-21537 is a security advisory published by Microsoft Security Response Center (MSRC) with High severity. Microsoft Defender for Endpoint Linux Extension Remote Code Execution Vulnerability

Which CVE IDs does CVE-2026-21537 cover?

CVE-2026-21537 covers the following CVE IDs: CVE-2026-21537. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-21537?

CVE-2026-21537 has a CVSS v3 base score of 8.8, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-21537?

CVE-2026-21537 affects 1 product, including: Microsoft Defender for Endpoint for Linux.

CVE-2026-21537HighCVSS 8.8

Microsoft Defender for Endpoint Linux Extension Remote Code Execution Vulnerability

Vendor

Microsoft Security Response Center (MSRC)

Published

February 10, 2026

Last Modified

—

🔗 CVE IDs covered (1)

CVE-2026-21537 →

📋 Description

Improper control of generation of code ('code injection') in Microsoft Defender for Linux allows an unauthorized attacker to execute code over an adjacent network.

🎯 Affected products1

Microsoft Defender for Endpoint for Linux

✅ Remediation

KBRelease Notes (Security Update) — fixed build 1.0.9.0

🔗 References (2)

advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21537
referencehttps://learn.microsoft.com/en-us/azure/defender-for-cloud/integration-defender-for-endpoint?WT.mc_id=Portal-Microsoft_Azure_Security