CVE-2026-39813

CRITICAL EXPLOITED

FortiSandbox 4.4.0-4.4.8 and 5.0.0-5.0.5 - Path Traversal via '../filedir'

Title source: llm
STIX 2.1

Exploitation Summary

CVE-2026-39813 has been observed exploited in the wild (reported by VulnCheck KEV). EIP tracks 2 public exploits from researchers including HORKimhab, 0xBlackash.

AI-analyzed exploit summary The repository lacks actual exploit code or technical details about CVE-2026-39813, instead providing generic setup instructions and a script to download external content. The README is filled with disclaimers and ethical use statements but no substantive vulnerability analysis.

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.

Exploits (2)

github SUSPICIOUS
by HORKimhab · poc
https://github.com/HORKimhab/CVE-2026-39813

The repository lacks actual exploit code or technical details about CVE-2026-39813, instead providing generic setup instructions and a script to download external content. The README is filled with disclaimers and ethical use statements but no substantive vulnerability analysis.

Classification
Suspicious 90%
Attack Type
Other
Complexity
Theoretical
Reliability
Theoretical
Target: unknown
No auth needed
Prerequisites: none
mistral-large-3 · analyzed Jun 17, 2026 Full analysis →
nomisec WRITEUP
by 0xBlackash · infoleak
https://github.com/0xBlackash/CVE-2026-39813

This repository provides a detailed technical analysis of CVE-2026-39813, a critical path traversal vulnerability in Fortinet FortiSandbox. It includes root cause analysis, affected versions, impact assessment, and mitigation recommendations.

Classification
Writeup 90%
Attack Type
Info Leak
Complexity
Moderate
Reliability
Theoretical
Target: Fortinet FortiSandbox 4.4.0–4.4.8, 5.0.0–5.0.5
No auth needed
Prerequisites: Access to vulnerable FortiSandbox instance
mistral-large-3 · analyzed Apr 24, 2026 Full analysis →

References (1)

Core 1

Scores

CVSS v3 9.8
EPSS 0.2306
EPSS Percentile 97.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

VulnCheck KEV 2026-06-15
CWE
CWE-24
Status published
Products (6)
Fortinet/FortiSandbox 4.4.0 - 4.4.8
fortinet/fortisandbox 4.4.0 - 4.4.9
Fortinet/FortiSandbox 5.0.0 - 5.0.5
Fortinet/FortiSandbox Cloud 23.4
Fortinet/FortiSandbox Cloud 24.1
Fortinet/FortiSandbox Cloud 5.0.4 - 5.0.5
Published Apr 14, 2026
Tracked Since Apr 14, 2026