CVE-2026-21537 is a critical code injection vulnerability in Microsoft Defender for Linux, allowing an unauthenticated attacker to execute arbitrary code over an adjacent network. With a CVSS score of 8.8 (High), this flaw requires no user interaction and grants full confidentiality, integrity, and availability impact. While there is no known active exploitation or public exploit code (Metasploit, Nuclei, ExploitDB), the vulnerability has garnered significant community attention with four mentions and four media articles, indicating a high level of awareness. Organizations using Microsoft Defender for Linux should prioritize patching to mitigate this severe risk.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
Range not provided by sourceCPE matchmatch criteria | cpe:2.3:a:microsoft:defender_for_endpoint:-:*:*:*:*:linux:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.
The average CVE in this peer group has 0.2 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.