Actively exploited KEV catalog No authentication
CVE-2026-104286

Fortinet FortiMail Path Traversal Vulnerability

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,…

CheckOps priority index
5.9/10 Patch within 7 days
Severity9.8
Probability0.5
Exploitation3/5

Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.

EPSS · today 4.6% higher than 91.6% of CVEs
CVSS 3.1 9.8 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:
Exploited for 33 days 01 Oct 2026
CISA due date 04 Oct 2026 for US federal agencies

Exploitation probability EPSS · FIRST

05010002 Oct10 Oct18 Oct25 Oct02 Nov
EPSS probability (%)Percentile among all CVEs

Exploitation signals 3 / 5

  • KEV catalog (CISA)01 Oct 2026
  • Exploited in EUVD (ENISA)01 Oct 2026
  • Used by ransomwareno
  • EPSS above 10 %4.6%
  • No account, over the networkyes

What to do

Fix

Apply the vendor’s fix as soon as it is available.

CISA guidance: 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.

Meanwhile

Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.

Manufacturers (CRA)

Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained

Description ENISA EUVD

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, FortiMail 7.0 all versions may allow an unauthenticated attacker to write arbitrary files on the underlying system via crafted HTTP or HTTPS requests.

Affected products

FortiMail
Affected versions
  • 8.0.0 ≤8.0.1
  • 7.6.0 ≤7.6.6
  • 7.0.0 ≤7.0.9
  • 7.4.0 ≤7.4.8
  • 7.2.0 ≤7.2.9
Weaknesses (CWE)

Open source packages OSV

Affected libraries according to OSV, with fixed versions.

Timeline

  1. Published

  2. Exploitation reported (ENISA)

  3. Added to the KEV catalog

  4. CISA remediation due date

References

Other exploited vulnerabilities from the same vendor

  • CVE-2025-61624Fortinet Multiple Products Path Traversal Vulnerability
    3.4 · Rising fast
  • CVE-2025-25249Fortinet Multiple Products Heap-based Buffer Overflow Vulnerability
    4.9 · Actively exploited
  • CVE-2025-68686Fortinet FortiOS Exposure of Sensitive Information to an Unauthorized Actor Vulnerability
    5.4 · Actively exploited
  • CVE-2026-39808Fortinet FortiSandbox OS Command Injection Vulnerability
    8.8 · Actively exploited
  • CVE-2026-25089Fortinet FortiSandbox OS Command Injection Vulnerability
    8.3 · Actively exploited
  • CVE-2026-21643Fortinet FortiClient EMS SQL Injection Vulnerability
    9.0 · Background exploitation

Are you affected?

CheckOps reads your SBOMs and scans, and alerts you as soon as one of your dependencies is exploited.

Get notified at launch

Sources: CISA KEV · ENISA EUVD · FIRST EPSS · OSV. Public data aggregated by CheckOps, updated automatically. Source texts remain the property of their authors. All exploited vulnerabilities