CVE-2026-55641 9router: Unauthenticated `/v1` proxy access via `Host`-header spoofing → open AI relay + SSRF

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...

CVE-2026-55641 9router: Unauthenticated `/v1` proxy access via `Host`-header spoofing → open AI relay + SSRF

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...

PT-2026-57220

Name of the Vulnerable Software and Affected Versions 9Router versions prior to 0.5.2 Description An unauthenticated remote attacker can bypass API-key authentication by sending a Host: localhost header, as the system incorrectly relies on the client-controlled Host header to determine if a reque...