CVE-2026-39813: Unauthenticated Authentication bypass and Privilege escalation in FortiSandbox

Published Apr 14, 2026
·
Updated

A Path Traversal vulnerability [CWE-24] in FortiSandbox JRPC API may allow an unauthenticated attacker to bypass authentication via specially crafted HTTP requests.

Other sources

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.

MITRE

Affected Software

4 affected componentsFixes available
Fortinet FortiSandbox>=5.0.0<=5.0.5
Fortinet FortiSandbox>=4.4.0<=4.4.8
Fortinet FortiSandbox>=4.4.0<4.4.9
Fortinet FortiSandbox>=5.0.0<5.0.6

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Fortinet FortiSandbox to a version that resolves this vulnerability.

    Fixed in 4.4.9
  2. Upgrade

    Upgrade Fortinet FortiSandbox to a version that resolves this vulnerability.

    Fixed in 5.0.6
  3. Upgrade

    Upgrade Fortinet FortiSandbox to a version that resolves this vulnerability.

    Fixed in 5.2.0

Event History

Apr 14, 2026
Advisory Published
via FortiGuard·12:00 AM
Data Sourced
via FortiGuard·12:00 AM
DescriptionSeverityWeaknessAffected Software
CVE Published
via MITRE·03:38 PM
Data Sourced
via MITRE·03:38 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·04:16 PM
DescriptionSeverityWeaknessAffected Software
Apr 15, 2026
News Published
via The Register·05:52 PM
News Published
via The Register·05:54 PM
Jun 16, 2026
News Published
via BleepingComputer·09:19 AM
News Published
via BleepingComputer·09:21 AM
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Frequently Asked Questions

1

What is the severity of CVE-2026-39813?

CVE-2026-39813 has been classified as a critical vulnerability due to its potential for unauthenticated authentication bypass and privilege escalation.

2

How do I fix CVE-2026-39813?

To fix CVE-2026-39813, update FortiSandbox to version 5.0.6 or later for affected versions up to 5.0.5 and to version 4.4.9 or later for affected versions up to 4.4.8.

3

Who is affected by CVE-2026-39813?

CVE-2026-39813 affects FortiSandbox versions between 5.0.0 and 5.0.5 as well as versions between 4.4.0 and 4.4.8.

4

What type of attack can exploit CVE-2026-39813?

CVE-2026-39813 can be exploited by an unauthenticated attacker through specially crafted HTTP requests to bypass authentication.

5

What is the impact of CVE-2026-39813 on FortiSandbox?

The impact of CVE-2026-39813 includes the ability for attackers to gain unauthorized access and execute operations that should be restricted.

Contact

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