How severe is CVE-2026-104286?

CVE-2026-104286 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-104286 being actively exploited?

Yes. CVE-2026-104286 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-10-01, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2026-104286?

CVE-2026-104286 affects Fortinet Fortimail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-104286?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

When was CVE-2026-104286 published?

CVE-2026-104286 was published on 2026-10-01 and last updated on 2026-10-02.

CVE-2026-104286

CVE-2026-104286 is a critical-severity vulnerability in Fortinet Fortimail with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-10-01). The underlying weakness is classified as CWE-22.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Yes — listed in CISA KEV (added 2026-10-01)
Weakness: CWE-22
Affected product: Fortinet Fortimail
Published: 2026-10-01
Last modified: 2026-10-02

Description

An improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0 through 7.4.8, FortiMail 7.2.0 through 7.2.9 may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.

Frequently asked questions

What is CVE-2026-104286?: An improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0 through 7.4.8, FortiMail 7.2.0 through 7.2.9 may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.
How severe is CVE-2026-104286?: CVE-2026-104286 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-104286 being actively exploited?: Yes. CVE-2026-104286 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-10-01, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-104286?: CVE-2026-104286 affects Fortinet Fortimail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-104286?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
When was CVE-2026-104286 published?: CVE-2026-104286 was published on 2026-10-01 and last updated on 2026-10-02.

References

Affected products (1)

cpe:2.3:a:fortinet:fortimail:*:*:*:*:*:*:*:*

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