# CVE-2026-39808: FortiSandbox - RCE

> Live exploitation tracking for CVE-2026-39808 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2026-39808

## Key facts

- **Exploitation phase:** Limited Exploitation. The vulnerability is known but shows very limited attacker interest or exploitation activity.
- **CVSS score:** 9.1
- **Public exploit available:** Yes
- **Affected products:** Fortinet FortiSandbox, Fortinet FortiSandbox PaaS
- **Weaknesses:** CWE-78 (Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'))
- **Tags:** enterprise_software

## 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 on the affected systems

## CrowdSec analysis

[CVE-2026-39808](https://euvd.enisa.europa.eu/vulnerability/CVE-2026-39808) is a critical OS command injection vulnerability in Fortinet FortiSandbox versions 4.4.0 through 4.4.8 and FortiSandbox PaaS, which allows remote attackers to execute unauthorized code or commands on the affected systems. Exploiting this flaw could enable threat actors to gain full control over the device, potentially leading to data breaches, system compromise, or further attacks within the network.

CrowdSec has been tracking this vulnerability and its exploits since 17th of June 2026.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2026-39808 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning.
Telemetry from the CrowdSec network also shows that exploitation activity for CVE-2026-39808 remains steady week-over-week. Attack volumes are consistent with long-term trends, indicating sustained interest from threat actors. CVE-2026-39808 continues to be an active part of the threat landscape and will likely remain this way for the forseeable future.

Attackers exploit the `/fortisandbox/job-detail/tracer-behavior` endpoint by injecting OS commands into the `jid` parameter, enabling unauthorized command execution and file creation on the system. Subsequent requests to `/ng/<filename>.txt` are used to verify successful exploitation.

## Timeline

- 2026-04-14: CVE Published. CVE-2026-39808 is published to NVD.
- 2026-06-17: Rule Released. CrowdSec releases a rule to detect CVE-2026-39808 exploitation attempts against the CrowdSec Network.
- 2026-06-17: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2026-39808 for the first time.
- 2026-07-16: CISA KEV. CVE-2026-39808 is added to the Known Exploited Vulnerabilities catalog by CISA.
- 2026-07-19: CISA Remediation Deadline. Expiration of the CISA remediation deadline as described in [BOD 22-01](https://www.cisa.gov/news-events/directives/bod-22-01-reducing-significant-risk-known-exploited-vulnerabilities).

## References

- https://github.com/samu-delucas/CVE-2026-39808
- https://fortiguard.fortinet.com/psirt/FG-IR-26-100
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-39808.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2026-39808) follows observed exploitation activity for CVE-2026-39808. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.