---
id: "CVE-2026-126237"
page: "https://infrastack.ai/live/CVE-2026-126237"
kind: "vulnerability"
aliases: ["CVE-2026-126237"]
title: "Fortinet FortiAuthenticator: crafted TCP requests can hang the appliance"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "vendor"
products: []
ecosystems: []
tags: ["fortiauthenticator", "fortinet", "self-hosted", "vendor"]
not_affected_if: ["unaffected-version"]
published_at: "2026-11-11T22:17:23+00:00"
first_seen_at: "2026-11-11T22:29:32+00:00"
updated_at: "2026-11-11T22:32:03+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-126237", "first_seen_at": "2026-11-11T22:29:32+00:00"}]
exploit_sources: []
---

# Fortinet FortiAuthenticator: crafted TCP requests can hang the appliance

Link for people: https://infrastack.ai/live/CVE-2026-126237 (this .md is for agents)

FortiAuthenticator versions 8.0.0 through 8.0.3 and 6.6.0 through 6.6.10 contain an infinite loop that crafted TCP requests can trigger. An attacker can use this to cause a denial of service.

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

## How to check

- Check the installed FortiAuthenticator version in the admin interface or with `get system status` on the appliance.
- Compare it against the affected ranges: `8.0.0` through `8.0.3` and `6.6.0` through `6.6.10`.

## Fix

- Fixed versions are not stated in the sources.

## Timeline

- 2026-11-11T22:29:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-126237

## From the sources

A loop with unreachable exit condition ('infinite loop') vulnerability in Fortinet FortiAuthenticator 8.0.0 through 8.0.3, FortiAuthenticator 6.6.0 through 6.6.10 may allow an attacker to cause a denial of service via crafted TCP requests.

---

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