CVE-2026-39813 Path traversal in FortiSandbox

What is CVE-2026-39813?

CVE-2026-39813 is a critical path traversal vulnerability in Fortinet Fortisandbox, published on 14 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A path traversal: '../filedir' vulnerability in Fortinet FortiSandbox 5.0.0 through 5.0.5, FortiSandbox 4.4.0 through 4.4.8 may allow attacker to escalation of privilege via specially crafted HTTP requests.

Weakness: CWE-24

Which versions are affected by CVE-2026-39813?

It affects 1 product.

Products include Fortinet Fortisandbox.

How do I fix CVE-2026-39813?

No fix has been published for CVE-2026-39813 yet. Limit exposure of the affected software until one is available.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-39813 being exploited?

There is no known exploitation of CVE-2026-39813 in the wild and no public exploit code.

Public exploit code: 2 proofs of concept on GitHub.

Other vulnerabilities in Fortinet Fortisandbox

• CVE-2026-25089 Fortinet FortiSandbox OS Command Injection Exploited Critical 9.1
• CVE-2026-39808 Fortinet FortiSandbox OS Command Injection Exploited Critical 9.1
• CVE-2026-26083 Missing authorization in FortiSandbox Critical 9.1
• CVE-2020-29011 SQL injection in Fortinet FortiSandbox High 8.8
• CVE-2021-26097 Command injection in Fortinet FortiSandbox High 8.8

All Fortinet Fortisandbox vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-5f64-p6cf-vvqg.