CVE-2026-104286: Fortinet FortiMail Path Traversal Vulnerability

Required action (CISA's text)

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.

Description (NVD)

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.

SOURCES

• CISA KEVCISA Known Exploited Vulnerabilities catalog

Other Fortinet flaws

• CVE-2025-61624: Fortinet Multiple Products Path Traversal Vulnerability
• CVE-2025-25249: Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
• CVE-2025-68686: Fortinet FortiOS Exposure of Sensitive Information to an Unauthorized Actor Vulnerability
• CVE-2026-39808: Fortinet FortiSandbox OS Command Injection Vulnerability
• CVE-2026-25089: Fortinet FortiSandbox OS Command Injection Vulnerability

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.