What is CVE-2019-5586?

CVE-2019-5586 is a medium-severity vulnerability in Fortinet Fortios, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-06-04.

How severe is CVE-2019-5586?

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

XSS in Fortinet Fortios

CVE-2019-5586

A reflected Cross-Site-Scripting (XSS) vulnerability in Fortinet FortiOS 5.2.0 to 5.6.10, 6.0.0 to 6.0.4 under SSL VPN web portal may allow an attacker to execute unauthorized malicious script code via the "param" parameter of the error process HTTP requests.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2019-06-04 · 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: 0.008 (55.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.9% 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: 0.008 · change: 0.000

Affected products

Fortinet Fortios — versions FortiOS 5.2.0 to 6.0.4
Fortinet Fortios

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

fortiguard.com/advisory/FG-IR-19-034 (Mitigation, Vendor Advisory)
www.securityfocus.com/bid/108610 (vdb-entry)

Frequently asked questions

What is CVE-2019-5586?: CVE-2019-5586 is a medium-severity vulnerability in Fortinet Fortios, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2019-06-04.
How severe is CVE-2019-5586?: Medium severity. CVSS v3 base score is 6.1 out of 10.