P1 Verified
Fortinet warns of critical FortiMail flaw exploited in zero-day attacks
CVE-2026-104286 affects Fortinet FortiMail. EPSS 0.02201 (percentile 0.81912), scored 2026-10-03. Listed in CISA KEV, added 2026-10-01.
- CVE / CWE
- CVE-2026-104286 / CWE-22, CWE-158
- Vendor / product
- Fortinet / FortiMail
- Severity
- 80.0
- CVSS
- Unavailable · ·
- EPSS
- 0.02201 · percentile 0.81912 · 2026-10-03
- KEV
- yes · added 2026-10-01 · due 2026-10-04 · ransomware use Unknown
- Exploit signals
- kev: CISA KEV listing.
- Signal evidence
Affected products
Required action — 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.
Provenance
- CISA Known Exploited Vulnerabilities Catalog (JSON) · Source record · observed 2026-10-04 05:55:03.893835+00:00 UTC
- FIRST EPSS daily exploit-probability · Source record · observed 2026-10-04 05:55:10.544390+00:00 UTC
- BleepingComputer · Source record · observed 2026-10-04 08:01:51.339284+00:00 UTC
Stable permalink: https://cybercodered.org/item/cve-cve-2026-104286.html