How severe is CVE-2021-26115?

CVE-2021-26115 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26115 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26115?

CVE-2021-26115 affects Fortinet Fortiwan. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26115?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2021-26115 have an EU (EUVD) identifier?

Yes. CVE-2021-26115 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-12936.

When was CVE-2021-26115 published?

CVE-2021-26115 was published on 2024-12-19 and last updated on 2026-06-17.

CVE-2021-26115

CVE-2021-26115 is a high-severity vulnerability in Fortinet Fortiwan with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 7.8)
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-12936
Weakness: CWE-78
Affected product: Fortinet Fortiwan
Published: 2024-12-19
Last modified: 2026-06-17

Description

An OS command injection (CWE-78) vulnerability in FortiWAN version 4.5.7 and below Command Line Interface may allow a local, authenticated and unprivileged attacker to escalate their privileges to root via executing a specially-crafted command.An OS command injection (CWE-78) vulnerability in FortiWAN Command Line Interface may allow a local, authenticated and unprivileged attacker to escalate their privileges to root via executing a specially-crafted command.

Frequently asked questions

What is CVE-2021-26115?: An OS command injection (CWE-78) vulnerability in FortiWAN version 4.5.7 and below Command Line Interface may allow a local, authenticated and unprivileged attacker to escalate their privileges to root via executing a specially-crafted command.An OS command injection (CWE-78) vulnerability in FortiWAN Command Line Interface may allow a local, authenticated and unprivileged attacker to escalate their privileges to root via executing a specially-crafted command.
How severe is CVE-2021-26115?: CVE-2021-26115 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26115 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26115?: CVE-2021-26115 affects Fortinet Fortiwan. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26115?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-26115 have an EU (EUVD) identifier?: Yes. CVE-2021-26115 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-12936.
When was CVE-2021-26115 published?: CVE-2021-26115 was published on 2024-12-19 and last updated on 2026-06-17.

References

https://fortiguard.fortinet.com/psirt/FG-IR-21-069

Affected products (1)

cpe:2.3:a:fortinet:fortiwan:*:*:*:*:*:*:*:*

More vulnerabilities in Fortinet Fortiwan

CVE-2021-26102 — Critical (CVSS 9.8): A relative path traversal vulnerability (CWE-23) in FortiWAN version 4.5.7 and below, 4.4 all versions may allow a…
CVE-2021-26114 — Critical (CVSS 9.8): Multiple improper neutralization of special elements used in an SQL command vulnerabilities in FortiWAN before 4.5.9…
CVE-2023-44252 — High (CVSS 8.8): ** UNSUPPORTED WHEN ASSIGNED **An improper authentication vulnerability [CWE-287] in Fortinet FortiWAN version 5.2.0…
CVE-2022-33869 — High (CVSS 8.8): An improper neutralization of special elements used in an OS command vulnerability [CWE-78] in the management…
CVE-2016-4965 — High (CVSS 8.8): Fortinet FortiWan (formerly AscernLink) before 4.2.5 allows remote authenticated users with access to the nslookup…
CVE-2023-44251 — High (CVSS 8.3): ** UNSUPPORTED WHEN ASSIGNED **A improper limitation of a pathname to a restricted directory ('path traversal')…

All CVEs affecting Fortinet Fortiwan →

Other CWE-78 (OS Command Injection) vulnerabilities

CVE-2026-19188 — Critical (CVSS 10.0): A critical OS command injection vulnerability has been identified in the Haiwell IoT Cloud HMI Gateway product. The…
CVE-2026-48362 — Critical (CVSS 10.0): ColdFusion is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')…
CVE-2026-16812 — Critical (CVSS 10.0): VeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access…
CVE-2026-6516 — Critical (CVSS 10.0): Zohocorp ManageEngine ADAudit Plus versions before 8606 are affected by Unauthenticated Remote code execution due to…
CVE-2026-46339 — Critical (CVSS 10.0): 9Router is an AI router & token saver. From 0.4.30 until 0.4.37, 9Router's src/proxy.js middleware did not protect…
CVE-2026-59726 — Critical (CVSS 10.0): Ruflo is an agent meta-harness for Claude Code and Codex. Prior to 3.16.3, ruflo's default docker-compose deployment…

Browse all CWE-78 (OS Command Injection) vulnerabilities →