CVE-2019-16151 Cross-site scripting in FortiOS

What is CVE-2019-16151?

CVE-2019-16151 is a medium-severity cross-site scripting vulnerability in Fortinet Fortios, published on 21 Mar 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

An improper neutralization of input during web page generation vulnerability [CWE-79] in FortiOS 6.4.1 and below, 6.2.9 and below may allow a remote unauthenticated attacker to either redirect users to malicious websites via a crafted "Host" header or to execute JavaScript code in the victim's browser context. This happens when the FortiGate has web filtering and category override enabled/configured.

Weakness: CWE-79

Which versions are affected by CVE-2019-16151?

It affects 1 product.

Products include Fortinet Fortios.

How do I fix CVE-2019-16151?

No fix has been published for CVE-2019-16151 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-2019-16151 being exploited?

There is no known exploitation of CVE-2019-16151 in the wild and no public exploit code.

Other vulnerabilities in Fortinet Fortios

• CVE-2024-23113 Fortinet Multiple Products Format String Exploited Critical 9.8
• CVE-2022-40684 Fortinet Multiple Products Authentication Bypass Exploited Critical 9.8
• CVE-2024-55591 Fortinet FortiOS and FortiProxy Authentication Bypass Exploited Critical 9.6
• CVE-2024-21762 Fortinet FortiOS Out-of-Bound Write Exploited Critical 9.6
• CVE-2022-42475 Fortinet FortiOS Heap-Based Buffer Overflow Exploited Critical 9.3

All Fortinet Fortios vulnerabilities

Sources

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

Also known as GHSA-c55x-8r3h-3586.