high8.2
CVE-2026-55641
9router: Unauthenticated `/v1` proxy access via `Host`-header spoofing → open AI relay + SSRF
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | 9router | < 0.5.2 | 0.5.2 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-86m2-fcxq-5q7c
- https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c
- https://nvd.nist.gov/vuln/detail/CVE-2026-55641
- https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3
- https://github.com/decolua/9router/releases/tag/v0.5.2