How severe is CVE-2021-26112?

CVE-2021-26112 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26112 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26112?

CVE-2021-26112 affects Fortinet Fortiwan. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26112?

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.

When was CVE-2021-26112 published?

CVE-2021-26112 was published on 2022-04-06 and last updated on 2026-06-17.

CVE-2021-26112

CVE-2021-26112 is a high-severity vulnerability in Fortinet Fortiwan with a CVSS 3.x base score of 8.1. 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-787.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 7.5
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Fortinet Fortiwan
Published: 2022-04-06
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-26112?: 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.
How severe is CVE-2021-26112?: CVE-2021-26112 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26112 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26112?: CVE-2021-26112 affects Fortinet Fortiwan. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26112?: 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.
When was CVE-2021-26112 published?: CVE-2021-26112 was published on 2022-04-06 and last updated on 2026-06-17.

References

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

Affected products (1)

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

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