Is CVE-2021-36186 actively exploited?

No active exploitation of CVE-2021-36186 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-36186 be exploited remotely?

Yes. CVE-2021-36186 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-36186?

CVE-2021-36186 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-36186

CRITICAL

CVE-2021-36186

CWE-787Published: November 2, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

A stack-based buffer overflow in Fortinet FortiWeb version 6.4.0, version 6.3.15 and below, 6.2.5 and below allows attacker to execute unauthorized code or commands via crafted HTTP requests

NVD Source

Technical Analysis

CVE-2021-36186 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.