OS command injection
Input changes a command that the server runs through its operating system.
CWE-78 · CISA KEV; NVD record: psirt@fortinet.com
Reading and practice labs · Free account for labs. Basic HTTP knowledge; some labs use Burp Suite.
Exploited. On CISA's list since 2026-07-16.
Fortinet FortiSandbox OS Command Injection Vulnerability
CVE-2026-39808 · Fortinet FortiSandbox · Published 2026-04-14
How bad would it be?
9.8 out of 10
CVSS rates it critical: about as damaging as flaws get.
How likely is it to be used?
93%
Estimated chance of exploitation in the next 30 days, among the top 1% of all scored flaws (EPSS, 2026-10-29).
Is it already being used?
Yes
CISA has seen it exploited in real attacks. For US government agencies the fix is deadline passed 103 days ago (2026-07-19).
What CISA says to do
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Fortinet FortiSandbox contains an OS command injection vulnerability that could allow an unauthenticated attacker to execute unauthorized code or commands via crafted HTTP requests.
What the flaw is
A improper neutralization of special elements used in an os command ('os command injection') vulnerability in Fortinet FortiSandbox 4.4.0 through 4.4.8 may allow attacker to execute unauthorized code or commands via <insert attack vector here>
From the NVD.
Fixes and advisories
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Exploited flaws from CISA's KEV catalogue. Chance of exploitation from EPSS by FIRST. Descriptions and scores from the NVD. This product uses the NVD API but is not endorsed or certified by the NVD.