Actively exploited · Published Apr 14, 2026 · Assigned by fortinet

CVE-2026-39808

Critical 9.1 Exploited

In plain English

A critical-severity OS command injection in FortiSandbox from Fortinet. Attackers are actively exploiting it in the wild (listed by CISA on July 16, 2026). The chance it is exploited in the next 30 days is estimated at 93.2% (higher than 99.8% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code. 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)9.1Critical
Exploit odds (30 days)93.2%top 0.2% of all CVEs
Exploited in the wildYesCISA KEV since Jul 16, 2026
Attack tooling2Nuclei, Public PoC

CISA guidance

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.

Federal agencies must remediate by Jul 19, 2026.

Official 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 products (as reported)

VendorProductVersions
Fortinet FortiSandbox 4.4.0 – through 4.4.8
Fortinet FortiSandbox PaaS 23.4.437423.4.435023.3.432923.1.424522.2.415122.2.413422.1.411321.4.4072

Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C

References