CVE-2026-39808
Fortinet FortiSandbox OS Command Injection Vulnerability
Fortinet FortiSandbox
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>
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 16 July 2026. US federal agencies were required to remediate it by 19 July 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 93.2%, which is higher than 99.8% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2026-39808 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2026-39808.
What does CVE-2026-39808 affect?
CVE-2026-39808 affects Fortinet FortiSandbox. 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>
How severe is CVE-2026-39808?
CVE-2026-39808 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 93.2%, higher than 99.8% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 19 July 2026.
How should organisations respond to CVE-2026-39808?
Apply the vendor patch for Fortinet FortiSandbox as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.