CISA KEV source record / CVE-2026-104286

Fortinet FortiMail Path Traversal Vulnerability

Fortinet / FortiMail

Known exploitation catalogNot a Secureline discoveryNot a live alert

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.

CVE identifier
CVE-2026-104286
Added to KEV
Oct 1, 2026
CISA catalog dueDate
Oct 4, 2026

The dates above are catalog fields. The addition date does not establish when the vulnerability was discovered or first exploited. Confirm which requirements apply to your organisation separately.

Publisher's 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.

This wording is attributed to the CISA snapshot. Verify current vendor guidance, affected versions and your deployment before applying changes.

Keep the signals separate.

Ransomware use, as reported by CISA
Unknown
CVSS severity
Not supplied by KEV
EPSS probability
Not available

No EPSS value was supplied for this record in the current snapshot. Unknown values are not treated as zero.

“Unknown” ransomware use is an unknown source field, not proof that ransomware activity has not occurred.

Source notes

https://fortiguard.fortinet.com/psirt/FG-IR-26-175 ; ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-104286

Source & freshness

Catalog version 2026.11.06
Source updated: Nov 6, 2026, 7:44 PM UTC
Successfully checked: Nov 7, 2026, 3:37 AM UTC

Automated source record, not an editorial advisory or an independent discovery. No affected or fixed version is inferred, and no organisation-specific risk rating is generated.