CVE-2026-55641

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

HIGH
8.2
CVSS Score
Published: July 10, 2026 at 03:36 PM UTC
Updated: October 25, 2026 at 03:10 PM UTC
1 product affected across 1 vendor9Router

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Severity
HIGH8.2
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.5.2
Affected range stops below 0.5.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-290CWE-348CWE-918CWE-1327

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