XSS in Fortinet Fortios

CVE-2019-16151

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2019-16151: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-16151?
CVE-2019-16151 is a medium-severity vulnerability in Fortinet Fortios, classified under Cross-site Scripting. CVSS score: 4.7/10. Published 2025-03-21.
How severe is CVE-2019-16151?
Medium severity. CVSS v3 base score is 4.7 out of 10.