How severe is CVE-2026-39808?

CVE-2026-39808 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-39808 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 49% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-39808?

CVE-2026-39808 affects Fortinet Fortisandbox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-39808?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-39808 have an EU (EUVD) identifier?

Yes. CVE-2026-39808 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22338.

When was CVE-2026-39808 published?

CVE-2026-39808 was published on 2026-04-14 and last updated on 2026-06-17.

CVE-2026-39808

CVE-2026-39808 is a critical-severity vulnerability in Fortinet Fortisandbox with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 49% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 49% (99th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-22338
Weakness: CWE-78
Affected product: Fortinet Fortisandbox
Published: 2026-04-14
Last modified: 2026-06-17

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>

Frequently asked questions

What is CVE-2026-39808?: 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 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-39808 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 49% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39808?: CVE-2026-39808 affects Fortinet Fortisandbox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39808?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-39808 have an EU (EUVD) identifier?: Yes. CVE-2026-39808 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-22338.
When was CVE-2026-39808 published?: CVE-2026-39808 was published on 2026-04-14 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:fortinet:fortisandbox:*:*:*:*:*:*:*:*

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