Exploited vulnerabilities / CVE-2026-104286
Confirmed exploited · path traversal · Fortinet FortiMailCVE-2026-104286
Fortinet FortiMail path traversal, confirmed exploited in the wild.
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.
| CISA's name for it | Fortinet FortiMail Path Traversal Vulnerability |
|---|---|
| Vendor and product | Fortinet · FortiMail |
| Type | path traversal · CWE-22, CWE-158 |
| Exploited | Confirmed by CISA listed 1 October 2026 |
| Likelihood | more likely to be exploited than most |
| Deadline | 4 October 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | fortiguard.fortinet.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Apply the vendor fix.
Assume files readable through the flaw were read: rotate secrets and keys stored on the system.
Restrict access to the interface until patched.
| CISA'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. |
|---|
Know before someone else finds it
Threat Landscape Monitoring fingerprints the software your internet-facing hosts disclose and matches it, every day, against this list and the exploitation scores. When a new entry touches something you run, you are told once, with the host and the fix. The free plan covers one domain.
CVE-2026-104286 in short
Is CVE-2026-104286 being exploited?
Yes. CISA added CVE-2026-104286 to its Known Exploited Vulnerabilities catalogue on 1 October 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2026-104286?
US federal agencies must remediate it by 4 October 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2026-104286 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 4.6%, the 91st percentile of every CVE it scores.
How do I fix CVE-2026-104286?
Apply the vendor fix. Assume files readable through the flaw were read: rotate secrets and keys stored on the system. Restrict access to the interface until patched.
Other Fortinet vulnerabilities being exploited
| CVE | Product | Type | Listed |
|---|---|---|---|
| CVE-2025-61624 | Multiple Products | path traversal | 16 October 2026 |
| CVE-2025-25249 | Multiple Products | memory corruption | 9 September 2026 |
| CVE-2025-68686 | FortiOS | exploited vulnerability | 27 July 2026 |
| CVE-2026-25089 | FortiSandbox | command injection | 16 July 2026 |
| CVE-2026-39808 | FortiSandbox | command injection | 16 July 2026 |
| CVE-2026-21643 | FortiClient EMS | SQL injection | 13 April 2026 |
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.