What is CVE-2021-36169?

CVE-2021-36169 is a medium-severity vulnerability in Fortinet Fortios. CVSS score: 4.2/10. Published 2021-12-13.

How severe is CVE-2021-36169?

Medium severity. CVSS v3 base score is 4.2 out of 10.

Vulnerability in Fortinet Fortios

CVE-2021-36169

A Hidden Functionality in Fortinet FortiOS 7.x before 7.0.1, FortiOS 6.4.x before 6.4.7 allows attacker to Execute unauthorized code or commands via specific hex read/write operations.

Published 2021-12-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (14.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Fortinet Fortios — versions FortiOS 7.0.0, 6.4.6, 6.2.9
Fortinet Fortios — versions 7.0.0

References

fortiguard.com/advisory/FG-IR-21-091 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-36169?: CVE-2021-36169 is a medium-severity vulnerability in Fortinet Fortios. CVSS score: 4.2/10. Published 2021-12-13.
How severe is CVE-2021-36169?: Medium severity. CVSS v3 base score is 4.2 out of 10.