CVE-2026-25089: Fortinet FortiSandbox OS Command Injection Vulnerability

This vulnerability is an OS command injection flaw in Fortinet FortiSandbox, FortiSandbox Cloud, and FortiSandbox PaaS. An unauthenticated attacker can execute unauthorized operating-system commands by sending specifically crafted HTTP requests. It matters because these products are deployed to analyze potentially malicious files and URLs; successful exploitation can give an attacker control over a security-analysis system.

How it works

The weakness is categorized as CWE-78, OS command injection. The product fails to properly sanitize or separate user-supplied input from operating-system command strings. An attacker supplies a crafted HTTP request that causes the application to concatenate attacker-controlled data into a command executed by the underlying operating system. Because the attack requires no authentication, any reachable interface that processes the malformed request can be abused. Exact request formats and affected code paths must be confirmed against the vendor advisory.

Am I affected? How to find it in your systems

FortiSandbox instances typically run as on-premises appliances, virtual machines, or cloud/PaaS services that receive files for detonation and analysis. Inventory all Fortinet FortiSandbox deployments, including any FortiSandbox Cloud or PaaS subscriptions. Identify management interfaces, API endpoints, and any network paths that accept unauthenticated or lightly authenticated HTTP traffic. Review product version and configuration details against the vendor advisory; no public version list is provided here. Look for log entries showing unexpected command execution, anomalous HTTP POST or GET requests to analysis or upload endpoints, or process-creation events originating from the sandbox service account.

How to remediate

Apply mitigations in accordance with vendor instructions. Confirm the exact update or configuration change required by checking the official Fortinet advisory for CVE-2026-25089. After patching, verify that the vulnerable code paths are no longer reachable and that logging of command execution and HTTP requests remains enabled.

If you can't patch immediately

• Restrict network exposure of FortiSandbox management and analysis interfaces to only the minimum necessary internal systems, consistent with CISA BOD 26-04 guidance.
• Place the appliance behind a network segmentation boundary that blocks direct internet access.
• Monitor HTTP request logs and process-creation events for indicators of command injection attempts.
• Evaluate whether the affected cloud or PaaS instance can be temporarily replaced or isolated until mitigations are applied.

If your data may have been exposed

Actively exploited vulnerabilities of this class have led to unauthorized access and subsequent data exposure in other environments. Organizations can run a free exposure scan of their email domains to check for presence in known breach data sets.