What is CVE-2018-9186?

CVE-2018-9186 is a medium-severity vulnerability in Fortinet Fortiauthenticator, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-05-31.

How severe is CVE-2018-9186?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Fortinet Fortiauthenticator

CVE-2018-9186

A cross-site scripting (XSS) vulnerability in Fortinet FortiAuthenticator in versions 4.0.0 to before 5.3.0 "CSRF validation failure" page allows attacker to execute unauthorized script code via inject malicious scripts in HTTP referer header.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2018-05-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.007 (53.3th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.007 · change: -0.000

Affected products

Fortinet Fortiauthenticator
Fortinet, Inc. Fortiauthenticator — versions below 5.3.0 versions

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

fortiguard.com/advisory/FG-IR-18-059 (Vendor Advisory)
www.securityfocus.com/bid/104371 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2018-9186?: CVE-2018-9186 is a medium-severity vulnerability in Fortinet Fortiauthenticator, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-05-31.
How severe is CVE-2018-9186?: Medium severity. CVSS v3 base score is 6.1 out of 10.