What is CVE-2016-4066?

CVE-2016-4066 is a high-severity vulnerability in Fortinet Fortiweb, classified under Cross-Site Request Forgery (CSRF). CVSS score: 8.8/10. Published 2016-07-13.

How severe is CVE-2016-4066?

High severity. CVSS v3 base score is 8.8 out of 10.

CSRF in Fortinet Fortiweb

CVE-2016-4066

Cross-site request forgery (CSRF) vulnerability in Fortinet FortiWeb before 5.5.3 allows remote attackers to hijack the authentication of administrators for requests that change the password via unspecified vectors.

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2016-07-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.009 (58.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Fortinet Fortiweb

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

fortiguard.com/advisory/fortiweb-csrf-vulnerability (Vendor Advisory)
www.securitytracker.com/id/1036194 (vdb-entry)
www.securityfocus.com/bid/91768 (vdb-entry)

Frequently asked questions

What is CVE-2016-4066?: CVE-2016-4066 is a high-severity vulnerability in Fortinet Fortiweb, classified under Cross-Site Request Forgery (CSRF). CVSS score: 8.8/10. Published 2016-07-13.
How severe is CVE-2016-4066?: High severity. CVSS v3 base score is 8.8 out of 10.