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Vulnerability record · CVE-2021-26112 · published 6 April 2022

CVE-2021-26112: Fortinet fortiwan out-of-bounds write vulnerability

Fortinet · Fortiwan

Multiple stack-based buffer overflow vulnerabilities [CWE-121] both in network daemons and in the command line interpreter of FortiWAN before 4.5.9 may allow an unauthenticated attacker to potentially corrupt control data in memory and execute arbitrary code via specifically crafted requests.

9.8 CVSS 3.1 Critical EPSS 1.7% · top 23.1% CWE-787 · Out-of-bounds write
9.8CVSS 3.1 base score, v2 7.5
1.7%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

Multiple stack-based buffer overflow vulnerabilities [CWE-121] both in network daemons and in the command line interpreter of FortiWAN before 4.5.9 may allow an unauthenticated attacker to potentially corrupt control data in memory and execute arbitrary code via specifically crafted requests.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://fortiguard.com/psirt/FG-IR-21-065 PatchVendor Advisory
https://fortiguard.com/psirt/FG-IR-21-065 PatchVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-26114Fortinet fortiwan sql injection vulnerabilityMultiple improper neutralization of special elements used in an SQL command vulnerabilities in FortiWAN before 4.5.9 may allow an unauthenticated att…EPSS 1.6%9.1CVE-2021-26102Fortinet fortiwan path traversal vulnerabilityA relative path traversal vulnerability (CWE-23) in FortiWAN version 4.5.7 and below, 4.4 all versions may allow a remote non-authenticated attacker …EPSS 20%8.8CVE-2023-44251Fortinet fortiwan path traversal vulnerability** UNSUPPORTED WHEN ASSIGNED **A improper limitation of a pathname to a restricted directory ('path traversal') vulnerability [CWE-22] in Fortinet Fo…EPSS 0.84%8.8CVE-2023-44252Fortinet fortiwan improper authentication vulnerability** UNSUPPORTED WHEN ASSIGNED **An improper authentication vulnerability [CWE-287] in Fortinet FortiWAN version 5.2.0 through 5.2.1 and version 5.1.1 …EPSS 0.72%8.8CVE-2022-33869Fortinet fortiwan os command injection vulnerabilityAn improper neutralization of special elements used in an OS command vulnerability [CWE-78] in the management interface of FortiWAN 4.0.0 through 4.5…EPSS 1.3%8.8CVE-2021-24009Fortinet fortiwan os command injection vulnerabilityMultiple improper neutralization of special elements used in an OS command vulnerabilities (CWE-78) in the Web GUI of FortiWAN before 4.5.9 may allow…EPSS 1.5%8.8CVE-2016-4965Fortinet fortiwan os command injection vulnerabilityFortinet FortiWan (formerly AscernLink) before 4.2.5 allows remote authenticated users with access to the nslookup functionality to execute arbitrary…EPSS 4.1%7.8CVE-2021-26115Fortinet fortiwan os command injection vulnerabilityAn OS command injection (CWE-78) vulnerability in FortiWAN version 4.5.7 and below Command Line Interface may allow a local, authenticated and unpriv…EPSS 0.79%

Source: NIST National Vulnerability Database (record CVE-2021-26112), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.