CVE-2026-104286: Fortinet FortiMail Path Traversal Vulnerability

Patch now

CRITICAL 9.8EXPLOITEDREMOTEUPGRADE

CVE-2026-104286 is a critical-severity flaw (CVSS 9.8) affecting fortimail, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Exploited in the wild (CISA KEV)
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.2% (top 18%)
CISA exploited list	Yes, fix due 2026-10-04
Weakness	CWE-22
Published	2026-10-01
Last modified	2026-10-07

Publisher (CNA): Fortinet, Inc. · Vendor: fortinet

Last updated 2026-10-07 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-01Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-10-01 20:17 UTCPublished CVE record published
2026-10-04Deadline CISA due date for US federal agencies to patch
2026-10-07 18:17 UTCUpdated Record last modified

fortinet fortimail UPGRADE

Affected: >= 7.2.0 and <= 7.4.8 · >= 7.6.0 and <= 7.6.6 · >= 8.0.0 and <= 8.0.1

Fixed in: newer than 8.0.1

Safe to downgrade to: a release before 7.2.0

1. Check installed version

apt-cache policy fortimail || rpm -q fortimail || fortimail --version

2. UPGRADE to newer than 8.0.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fortimail

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fortimail

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.2.0 (Debian / Ubuntu)

apt-cache madison fortimail sudo apt install fortimail=<VERSION_BEFORE_7.2.0> sudo apt-mark hold fortimail

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list fortimail sudo dnf downgrade fortimail-<VERSION_BEFORE_7.2.0> sudo dnf versionlock add fortimail

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · retext · FIXED · 8.1.0-1.fc46 · FEDORA-2026-0602a84203 · source

sudo dnf upgrade --advisory=FEDORA-2026-0602a84203

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: ShadowForge-Cyber/CVE-2026-104286-POC (0 stars)
GitHub PoC: techupdate24/fortimail-zero-day-cve-2026-104286 (0 stars)
GitHub PoC: kh20134/fortimail-cve-2026-104286-response (0 stars)

Advisories and coverage

Official advisories

CERT-SE Sweden: Kritisk sårbarhet i FortiMail 2026-10-02

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-104286?

fortimail: upgrade to newer than 8.0.1. Exact commands for each OS are on this page.

Is CVE-2026-104286 being exploited?

Yes. CVE-2026-104286 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-104286 affect?

CVE-2026-104286 affects fortimail. Severity is critical (CVSS 9.8). 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

How urgent is CVE-2026-104286?

Priority 88/100. Critical severity; Exploited in the wild (CISA KEV); CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

Fortinet vulnerabilities

References

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