Is CVE-2026-39808 being actively exploited?

Yes. CVE-2026-39808 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added on July 16, 2026.

What is the CVSS score for CVE-2026-39808?

CVE-2026-39808 has a CVSS 3.1 base score of 9.8 (CRITICAL).

CVE-2026-39808

CRITICAL · CVSS 9.8CISA KEV: actively exploitedEPSS 47.4%EU EUVD: exploited

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>

Key facts

CVSS score: 9.8 (v3.1)
Severity: CRITICAL
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-78
EPSS score: 47.4% (99th percentile)
In CISA KEV: Yes, added July 16, 2026
In EU EUVD: Yes (EUVD-2026-22338)
Published: April 14, 2026
NVD last modified: July 17, 2026
Status: Analyzed

CISA Known Exploited Vulnerability

Fortinet FortiSandbox OS Command Injection Vulnerability

Added to the KEV catalog on July 16, 2026; federal remediation due July 19, 2026.

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2026-22338 in the EU Vulnerability Database. ENISA flags it as known exploited. Last updated in EUVD on July 17, 2026.

View on the EU Vulnerability Database

Affected products

fortinet / fortisandbox

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

FortiSandbox 4.4 - Fortinet, Inc. - Common Criteria CCEVS-VR-VID-11636-2025 - active

References

https://fortiguard.fortinet.com/psirt/FG-IR-26-100(Vendor Advisory)
https://github.com/samu-delucas/CVE-2026-39808(Exploit, Third Party Advisory)
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-39808(US Government Resource)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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