CVE-2026-59838 Cross-site scripting in FortiSIEM

Medium 5.3 Published 15 Jul 2026 Updated 15 Jul 2026

An attacker can execute unauthorized code or commands via cross-site scripting in Fortinet FortiSIEM.

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-2026-59838?

CVE-2026-59838 is a medium-severity cross-site scripting vulnerability in Fortinet FortiSIEM, published on 15 Jul 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 script-related html tags in a web page (basic xss) vulnerability in Fortinet FortiSIEM 7.4.0, FortiSIEM 7.3.0 through 7.3.4, FortiSIEM 7.2.0 through 7.2.6, FortiSIEM 7.1 all versions, FortiSIEM 7.0 all versions, FortiSIEM 6.7 all versions, FortiSIEM 6.6 all versions, FortiSIEM 6.5 all versions, FortiSIEM 6.4 all versions may allow attacker to execute unauthorized code or commands via <insert attack vector here>

Weakness: CWE-80

Which versions are affected by CVE-2026-59838?

It affects 1 product.

Products include Fortinet Fortisiem.

How do I fix CVE-2026-59838?

No fix has been published for CVE-2026-59838 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-2026-59838 being exploited?

There is no known exploitation of CVE-2026-59838 in the wild and no public exploit code.

Sources

Also known as GHSA-qgv9-w22c-fhgv.