---
id: CVE-2026-55641
title: 9Router is an AI router & token saver
summary: >-
  9Router is an AI router & token saver. Prior to 0.5.2, 9router determines
  whether a /v1 LLM proxy request is local by reading the client-controlled Host
  header, allowing a remote unauthenticated attacker to send Host: localhost and
  bypas…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N'
cwe:
  - CWE-290
  - CWE-348
  - CWE-918
  - CWE-1327
published: '2026-07-10'
updated: '2026-07-10'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55641'
references:
  - url: >-
      https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3
    label: security-advisories@github.com
  - url: 'https://github.com/decolua/9router/releases/tag/v0.5.2'
    label: security-advisories@github.com
  - url: 'https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c'
    label: security-advisories@github.com
  - url: 'https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00323
epssPercentile: 0.25536
ingestedAt: '2026-07-11T20:15:26.081Z'
---

## Overview

9Router is an AI router & token saver. Prior to 0.5.2, 9router determines whether a /v1 LLM proxy request is local by reading the client-controlled Host header, allowing a remote unauthenticated attacker to send Host: localhost and bypass API-key authentication. In the default configuration, this exposes the /v1 proxy to upstream provider calls using stored provider credentials and allows /v1/search with the searxng provider_options.baseUrl parameter to drive server-side requests to internal or cloud-metadata hosts. This issue is fixed in version 0.5.2.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.