CVE-2026-39808

Fortinet FortiSandbox: OS Command Injection

As of , CVE-2026-39808 in Fortinet FortiSandbox is on CISA's list of exploited vulnerabilities: CISA listed it on . Our patch-first group: Patch now.

Exploited
Yes: CISA listed it on 16 July 2026
US federal deadline
19 July 20263 days after CISA listed it. US federal civilian agencies must fix it by then.
Used in ransomware campaigns
Not known to CISA
Forensic triage
Required by CISA under BOD 26-04Agencies must also look for signs that attackers already got in.
EPSS score
0.47Higher than 98% of the CVEs EPSS scores. EPSS estimates the chance of exploitation activity in the next 30 days.
Public exploit
None foundNeither Metasploit nor Exploit-DB lists one.
Fix
Vendor advice: fortiguard.fortinet.comLinks below, from CISA's entry.

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.

CISA's required action

What the flaw is

Fortinet FortiSandbox contains an OS command injection vulnerability that could allow an unauthenticated attacker to execute unauthorized code or commands via crafted HTTP requests.

CISA's description

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>

The CVE record's description, from fortinet

CVE published
14 April 2026
Assigned by
fortinet
CVSS
9.1 Critical (CVSS 3.1, from the CNA)
CWE-78
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CISA SSVC, exploitation
active
CISA SSVC, automatable
yes
CISA SSVC, technical impact
total

Timeline

  1. The CVE record was published.
  2. CISA added it to its list of exploited vulnerabilities.
  3. The US federal deadline to fix it.

FortiSandbox: other exploited entries

VulnerabilityProductOur groupListedDeadlineEPSS
CVE-2026-25089OS Command InjectionFortinet FortiSandboxPatch nowForensic triage required by CISA0.76

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