CVE-2026-104286 — Fortimail
CRITICALCVE-2026-104286 is a critical-severity (CVSS 9.8) Path Traversal vulnerability in fortinet fortimail. It is in CISA's Known Exploited Vulnerabilities catalog (added 2026-10-01) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.
An improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0…
Exploitation Status
Actively exploited in the wild
- Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2026-10-01. Federal agencies were required to remediate by 2026-10-04.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2026-104286.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-104286 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 383,485 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Description
An improper limitation of a pathname to a restricted directory ('path traversal') vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1, FortiMail 7.6.0 through 7.6.6, FortiMail 7.4.0 through 7.4.8, FortiMail 7.2.0 through 7.2.9 may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.
Affected Products
fortimailfortinetDetection & mitigation playbook
Vendor / applianceDetect
Inventory every fortinet fortimail deployment and check each version against the affected-products list above.
Remediation status
No patch has shipped for CVE-2026-104286 yet — track the fortinet fortimail advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.
Frequently Asked Questions
Is CVE-2026-104286 being exploited in your environment?
Detect and block the exploit chain at execution, on systems you cannot patch yet.