Critical SEVERITY — Vulnerability

CVE-2026-104286 — Fortinet FortiMail Path Traversal Vulnerability

Fortinet FortiMail contains a path traversal and an improper neutralization of NULL byte or NULL character vulnerability that may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.

Platform
FortiGate / FortiOS
CVE Record
CVE-2026-104286
Advisory
CISA-KEV
Published
01 October 2026
Views
5
Primary source: Review the official advisory at nvd.nist.gov Go to Source

Status

This vulnerability appears in CISA's catalog of known exploited vulnerabilities. It is not a theoretical risk — it is being used in the wild.

Description

Fortinet FortiMail contains a path traversal and an improper neutralization of NULL byte or NULL character vulnerability that may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.

Details

  • Vendor: Fortinet
  • Product: FortiMail
  • Added to catalog: 2026-10-01

Action Required by CISA

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

  • Due date for federal agencies: 2026-10-04
Fortinet FortiMail

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