9Router: Authentication Bypass in Public LLM API via Spoofable X-9r-Real-Ip Header (CVE-2026-56681) | HOL Guard CVE

High · CVSS 7.3CVE-2026-56681GHSA-5MJ8-GF6M-FHW8

9Router: Authentication Bypass in Public LLM API via Spoofable X-9r-Real-Ip Header

Answer in brief

CVE-2026-56681 records a High severity (CVSS 7.3) vulnerability in 9Router: Authentication Bypass in Public LLM API via Spoofable X-9r-Real-Ip Header. The current sources do not mark it as known exploited. The current feed maps decolua/9router (generic), 9router (npm). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 22, 2026Updated Sep 22, 2026Source checked Sep 22, 2026First seen by HOL Sep 22, 2026Material review Sep 22, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.3
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps decolua/9router (generic), 9router (npm). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
decolua/9routergeneric	<0.5.6	0.5.6
9routernpm	<=0.5.4	0.5.8

Recommended response

Check inventory. Check lockfiles and deployed manifests for decolua/9router, 9router.
Review the reported fix. Update decolua/9router to 0.5.6; 9router to 0.5.8 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 22, 2026

Sources and claim methodology

Upstream source description

9Router is an AI router & token saver. Prior to 0.5.6, 9Router deployments that allow requests to reach Next.js without the sanitizing custom-server.js wrapper trust the client-supplied X-9r-Real-Ip header in src/dashboardGuard.js when isLocalRequest decides whether canAccessPublicLlmApi may skip API-key validation for /api/v1/* routes. A remote unauthenticated attacker can set X-9r-Real-Ip to 127.0.0.1 and be classified as a local client, including on the verified GET /api/v1/models route. This permits unauthorized use of the instance owner's configured LLM providers, consumption of paid credits, and enumeration of configured providers and models. This issue is fixed in version 0.5.6.

Quoted source text, attributed separately from HOL analysis.