CVE-2026-55641

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-10 17:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-25 15:10 UTC Last updatedMost recent change to the record

Details

Published

2026-07-10 17:16 UTC

Last modified

2026-10-25 15:10 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-290

Record status

Deferred

Attack profile CVSS 3.1 · 8.2

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

Low

Availability

None