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 unau…

published 2021-11-02 5y ago modified 2026-06-17 4mo ago also EUVD-2021-22807

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.6%; EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits: 0; none known

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

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CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2y ago (2024-10-23)

Exploit prediction

1.61% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:X/RC:C
CNA	3.1	8.8	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

Fortinet Fortinet FortiWeb

Classification

Weakness

CWE-787 Out-of-bounds Write

Technology feeds

Fortinet rss critical rss

References

fortiguard.com /advisory/FG-IR-21-119
vendor-advisory

Sources

CVE List CVE-2021-36186
NVD CVE-2021-36186

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