CVE-2026-39812 Cross-site scripting in FortiSandbox
An attacker can execute unauthorized code or commands via cross-site scripting in Fortinet FortiSandbox, requiring an upgrade to mitigate.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-39812?
CVE-2026-39812 is a medium-severity cross-site scripting vulnerability in Fortinet Fortisandbox, published on 14 Apr 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
A improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Fortinet FortiSandbox 5.0.0 through 5.0.5, FortiSandbox 4.4.0 through 4.4.8, FortiSandbox 4.2 all versions, FortiSandbox PaaS 5.0.0 through 5.0.5, FortiSandbox PaaS 4.4.0 through 4.4.8, FortiSandbox PaaS 4.2 all versions may allow attacker to execute unauthorized code or commands via <insert attack vector here>
Weakness: CWE-79
Which versions are affected by CVE-2026-39812?
It affects 2 products.
Products include Fortinet Fortisandbox, Fortinet Fortisandbox Cloud.
How do I fix CVE-2026-39812?
No fix has been published for CVE-2026-39812 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-39812 being exploited?
There is no known exploitation of CVE-2026-39812 in the wild and no public exploit code.
Other vulnerabilities in Fortinet Fortisandbox
Sources
Also known as GHSA-9q3x-6267-mffc.