Threat Intelligence / CVE / CVE-2026-104286

CVE-2026-104286 — Fortinet FortiMail

CISA KEV
CVSS v3.1 9.8 (CRITICAL) · Priority 9/10 · Published 2026-10-01

As of 2026-10-01, CVE-2026-104286 is a CRITICAL-severity vulnerability in Fortinet FortiMail, CVSS v3.1 9.8. It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-10-01), with a US federal remediation deadline of 2026-10-04. Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-104286, most recently “Fortinet FortiMail critical path traversal flaw CVE-2026-104286 (FG-IR-26-175) exploited in zero-day attacks”.

Last updated: 2026-10-01

What is CVE-2026-104286?

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.

The record classifies CVE-2026-104286 under weakness class CWE-22. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 1 day ago.

Severity and exploitation probability

CVSS v3.1 base score
9.8 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C
CISA KEV
Listed since 2026-10-01, federal remediation deadline 2026-10-04
Threadlinqs priority
9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published
2026-10-01

Is CVE-2026-104286 being exploited?

CISA added CVE-2026-104286 to the Known Exploited Vulnerabilities catalog on 2026-10-01, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-10-04 under BOD 22-01. It currently carries a trending score of 40 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-104286

Because CVE-2026-104286 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-10-04. No vendor patch reference has been recorded for CVE-2026-104286 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-104286

1 tracked threat in the Threadlinqs corpus references CVE-2026-104286, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Enriched from CVE.org, CISA KEV, GitHub Security Advisories. Last verified by Threadlinqs on .

Other references

Full detection coverage & IOCs for threats exploiting CVE-2026-104286 are available via the Threadlinqs MCP server (Purple tier). View plans →

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