---
id: "CVE-2026-126163"
page: "https://infrastack.ai/live/CVE-2026-126163"
kind: "vulnerability"
aliases: ["CVE-2026-126163"]
title: "Fortinet FortiMail: crafted SMTP command lets unauthenticated attackers run code"
severity: "high"
cvss: 8.1
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: [{"name": "FortiMail", "fixed": ["8.0.2"], "affected": ">= 8.0.0, < 8.0.2", "ecosystem": "vendor"}]
ecosystems: []
tags: ["email-gateway", "fortimail", "fortinet", "infrastructure", "self-hosted", "smtp"]
not_affected_if: ["fortimail-cloud", "managed-hosting", "other-fortimail-versions", "version-7.4", "version-7.6"]
published_at: "2026-11-11T22:17:14+00:00"
first_seen_at: "2026-11-11T22:29:28+00:00"
updated_at: "2026-11-11T22:47:30+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126163", "first_seen_at": "2026-11-11T22:29:28+00:00"}, {"source": "analyst", "url": "https://fortiguard.fortinet.com/psirt/FG-IR-26-215", "first_seen_at": "2026-11-11T22:47:30+00:00", "cites": ["https://fortiguard.fortinet.com/psirt/FG-IR-26-215"]}]
exploit_sources: []
---

# Fortinet FortiMail: crafted SMTP command lets unauthenticated attackers run code

Link for people: https://infrastack.ai/live/CVE-2026-126163 (this .md is for agents)

A format string flaw in Fortinet FortiMail versions 8.0.0 through 8.0.1 is triggered by a specially crafted SMTP command. A remote attacker with no login may be able to execute unauthorized code or commands on the appliance.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:FortiMail affected >= 8.0.0, < 8.0.2 fixed 8.0.2

## How to check

Run 'get system status' on the appliance CLI or check the admin UI dashboard for the firmware version. Exposed if it is 8.0.0 or 8.0.1 (on-premises/self-managed) and SMTP is reachable by untrusted senders. 7.6.x and 7.4.x are not affected per the vendor. No virtual patch (IPS signature) is available per Fortinet.

## Fix

Upgrade FortiMail 8.0.x to 8.0.2 or later. FortiMail 7.6 and 7.4 are not affected. FortiMail Cloud was already updated by Fortinet on Oct 5, 2026.

## Timeline

- 2026-11-11T22:29:28+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-126163
- 2026-11-11T22:47:30+00:00 analyst https://fortiguard.fortinet.com/psirt/FG-IR-26-215 — Fortinet PSIRT FG-IR-26-215 read: affects 8.0.0-8.0.1, fixed 8.0.2; 7.6/7.4 not affected; FortiMail Cloud already patched Oct 5 2026; not exploited per vendor. X/community not searched (low-signal B).

## Documents

- [advisory] Fortinet PSIRT FG-IR-26-215: FortiMail format string (CVE-2026-126163) https://fortiguard.fortinet.com/psirt/FG-IR-26-215

## From the sources

A use of externally-controlled format string vulnerability in Fortinet FortiMail 8.0.0 through 8.0.1 may allow a remote unauthenticated attacker to execute unauthorized code or commands via a specially crafted SMTP command.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_