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Known Exploited Vulnerability
9.8
CRITICAL CVSS 3.1
CVE-2026-104286
Fortinet FortiMail Path Traversal Vulnerability - [Actively Exploited]
Overview
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.

Details
INFO

Published Date :

Oct. 1, 2026, 8:17 p.m.

Last Modified :

Oct. 7, 2026, 6:17 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

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.

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.

Known Ransomware Campaign Use:

Unknown

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

Impact
Affected Products

The following products are affected by CVE-2026-104286 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fortinet fortimail
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL 6abe59d8-c742-4dff-8ce8-9b0ca1073da8
CVSS 3.1 CRITICAL [email protected]
Solution
Update FortiMail to a patched version to prevent arbitrary file writes.
  • Update FortiMail to a version with the vulnerability resolved.
  • Apply vendor-supplied security patches.
  • Restrict access to affected services.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-104286.

URL Resource
https://fortiguard.fortinet.com/psirt/FG-IR-26-175 Mitigation Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-104286 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-104286 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-104286 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-104286 vulnerability anywhere in the article.

  • TheCyberThrone
Microsoft Releases Out-of-Band Exchange Security Update

October 6, 2026Executive SummaryMicrosoft has released an out-of-band security update for Exchange Server to address CVE-2026-96940, an Elevation of Privilege vulnerability that could allow an authent ... Read more

Published Date: Oct 06, 2026 (2 weeks, 1 day ago)
  • TheCyberThrone
CVE-2026-88779: NetScaler SAML Zero-Day Exploited in the Wild

A new Citrix NetScaler zero-day has moved quickly from discovery to active exploitation. CVE-2026-88779 affects NetScaler ADC and NetScaler Gateway deployments using SAML authentication and can cause ... Read more

Published Date: Oct 05, 2026 (2 weeks, 2 days ago)
  • security.nl
Belgische overheidsinstantie Belnet gehackt via Fortinet-zerodaylek

De Belgische overheidsinstantie Belnet is eerder dit jaar gehackt via een zerodaylek in Fortinet FortiMail, waarbij aanvallers maandenlang e-mails wisten te stelen, zo heeft de organisatie via de eige ... Read more

Published Date: Oct 05, 2026 (2 weeks, 2 days ago)
  • TheCyberThrone
CVE-2026-90970: Critical GitLab AI Gateway Vulnerability

October 3, 2026AI infrastructure is quickly becoming part of the enterprise attack surface, and CVE-2026-90970 is a good example of why.Zero-Day Vulnerability ReportsThe vulnerability affects GitLab A ... Read more

Published Date: Oct 03, 2026 (2 weeks, 4 days ago)
  • TheCyberThrone
FortiMail Zero-Day Exploited in the Wild — CVE-2026-104286

October 2, 2026Executive SummaryFortinet has confirmed active exploitation of a critical FortiMail zero-day, CVE-2026-104286. The vulnerability carries a CVSS score of 9.8 and can allow an unauthentic ... Read more

Published Date: Oct 02, 2026 (2 weeks, 5 days ago)
  • security.nl
Fortinet waarschuwt voor actief misbruikt path traversal-lek in FortiMail

vrijdag 2 oktober 2026, 09:00 door Redactie, 0 reactiesLaatst bijgewerkt: Vandaag, 09:30 Fortinet waarschuwt klanten voor een actief misbruikt path traversal-lek in FortiMail. Er zijn updates uitgebra ... Read more

Published Date: Oct 02, 2026 (2 weeks, 6 days ago)
  • The Hacker News
Critical FortiMail Zero-Day Flaw Exploited in Attacks Allows Unauthenticated Arbitrary File Writes

The U.S. Cybersecurity and Infrastructure Security Agency (CISA), on Thursday, added a critical security flaw impacting Fortinet FortiMail to its Known Exploited Vulnerabilities (KEV) catalog, followi ... Read more

Published Date: Oct 02, 2026 (2 weeks, 6 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-104286 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 07, 2026

    Action Type Old Value New Value
    Removed SSVC {'id': 'CVE-2026-104286', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-01T00:00:00+00:00'}
    Added SSVC {'id': 'CVE-2026-104286', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-02T03:55:37.976071Z'}
  • Initial Analysis by [email protected]

    Oct. 02, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:fortinet:fortimail:*:*:*:*:*:*:*:* versions from (including) 7.2.0 up to (including) 7.4.8 *cpe:2.3:a:fortinet:fortimail:*:*:*:*:*:*:*:* versions from (including) 7.6.0 up to (including) 7.6.6 *cpe:2.3:a:fortinet:fortimail:*:*:*:*:*:*:*:* versions from (including) 8.0.0 up to (including) 8.0.1
    Added Reference Type Fortinet, Inc.: https://fortiguard.fortinet.com/psirt/FG-IR-26-175 Types: Mitigation, Vendor Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-104286 Types: US Government Resource
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 02, 2026

    Action Type Old Value New Value
    Removed SSVC {'id': 'CVE-2026-104286', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-01T20:02:06.190902Z'}
    Added SSVC {'id': 'CVE-2026-104286', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-01T00:00:00+00:00'}
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Oct. 01, 2026

    Action Type Old Value New Value
    Added Date Added 2026-10-01
    Added Due Date 2026-10-01
    Added Required Action 2026-10-01
    Added Vulnerability Name 2026-10-01
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 01, 2026

    Action Type Old Value New Value
    Removed SSVC {'id': 'CVE-2026-104286', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-01T19:38:28.720380Z'}
    Added SSVC {'id': 'CVE-2026-104286', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-01T20:02:06.190902Z'}
  • New CVE Received by [email protected]

    Oct. 01, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-22
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/104xxx/CVE-2026-104286.json">CVE-2026-104286</a>
    Added Reference https://fortiguard.fortinet.com/psirt/FG-IR-26-175
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 01, 2026

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-104286
    Added SSVC {'id': 'CVE-2026-104286', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-10-01T19:38:28.720380Z'}
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 9.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact