CVEs / CVE-2026-39808
CVE-2026-39808: Fortinet FortiSandbox OS Command Injection Vulnerability
- Known exploited in the CISA KEV catalog since 16 Jul 2026
- critical 9.8 CVSS 3.1 (from the CNA)
- EPSS 93.1% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
Fortinet FortiSandbox contains an OS command injection vulnerability that could allow an unauthenticated attacker to execute unauthorized code or commands via crafted HTTP requests.
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>
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Fortinet FortiSandbox | from 4.4.0, up to and including 4.4.8 | — |
| Fortinet FortiSandbox PaaS | 23.4.4374 | — |
| Fortinet FortiSandbox PaaS | 23.4.4350 | — |
| Fortinet FortiSandbox PaaS | 23.3.4329 | — |
| Fortinet FortiSandbox PaaS | 23.1.4245 | — |
| Fortinet FortiSandbox PaaS | 22.2.4151 | — |
| Fortinet FortiSandbox PaaS | 22.2.4134 | — |
| Fortinet FortiSandbox PaaS | 22.1.4113 | — |
| Fortinet FortiSandbox PaaS | 21.4.4072 | — |
| Fortinet FortiSandbox PaaS | 21.3.4055 | — |
Exploitation
| In CISA KEV since | 16 Jul 2026 |
|---|---|
| Due date for US federal agencies | 19 Jul 2026 |
| Used in ransomware campaigns | Unknown |
| Required action | 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. |
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-78 |
References
- CVE-2026-39808 on NVD
- CVE-2026-39808 in the CISA KEV catalog
- https://fortiguard.fortinet.com/psirt/FG-IR-26-100 (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- 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
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.