Oct 19, 2026 · 13:48 UTC SEARCH
UNRATED KNOWN EXPLOITED
Vulnerability intelligence

CVE-2026-104286

VendorFortinet
ProductFortiMail
Known exploitedYes
Added to CISA KEVOctober 1, 2026
KEV due dateOctober 4, 2026
Known ransomware useNot identified by CISA

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.

Required action

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.

CISA KEV status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities Catalog. Known ransomware campaign use: Unknown.

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