CVE-2026-21537 Microsoft Defender for Endpoint Linux Extension Remote Code Execution Vulnerability
An unauthorized attacker can execute code over an adjacent network due to improper code generation in Microsoft Defender for Endpoint Linux.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-21537?
CVE-2026-21537 is a high-severity code injection vulnerability in Microsoft Defender for Endpoint for Linux, published on 10 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-94
Which versions are affected by CVE-2026-21537?
It affects 1 product.
Products include Microsoft Defender for Endpoint.
How do I fix CVE-2026-21537?
No fix has been published for CVE-2026-21537 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-21537 being exploited?
There is no known exploitation of CVE-2026-21537 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Defender for Endpoint for Linux
- CVE-2024-49057 Microsoft Defender for Endpoint on Android Spoofing Vulnerability
- CVE-2025-47161 Microsoft Defender for Endpoint Elevation of Privilege Vulnerability
- CVE-2024-21315 Microsoft Defender for Endpoint Protection Elevation of Privilege Vulnerability
- CVE-2022-35828 Microsoft Defender for Endpoint for Mac Elevation of Privilege Vulnerability
- CVE-2026-50658 Microsoft Defender for Endpoint for Mac Elevation of Privilege Vulnerability
Sources
Also known as GHSA-c8x6-p29h-wm35.