What is CVE-2021-41015?

CVE-2021-41015 is a medium-severity vulnerability in Fortinet Fortiweb, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-12-08.

How severe is CVE-2021-41015?

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

XSS in Fortinet Fortiweb

CVE-2021-41015

A improper neutralization of input during web page generation ('cross-site scripting') in Fortinet FortiWeb version 6.4.1 and below, 6.3.15 and below allows attacker to execute unauthorized code or commands via crafted HTTP requests to SAML login handler

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-12-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (55.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.7% 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 Fortiweb — versions FortiWeb 6.4.1, 6.4.0
Fortinet Fortiweb — versions 6.4.0, 6.4.1

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

fortiguard.com/advisory/FG-IR-21-139 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-41015?: CVE-2021-41015 is a medium-severity vulnerability in Fortinet Fortiweb, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-12-08.
How severe is CVE-2021-41015?: Medium severity. CVSS v3 base score is 6.1 out of 10.