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TI-2026-40863 Aliases CVE-2026-56681GHSA-5mj8-gf6m-fhw8

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

Priority HIGH 71CWE-807Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01114 66th percentileScored 2026-11-07
Fix Fixed 9router (decolua): 0.5.69router (npm): 0.5.8

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
decolua9routerbefore 0.5.60.5.6Patch availableCNA
—9router (npm)before 0.5.80.5.8Patch availableGHSA-5mj8-gf6m-fhw8
  • 9router Vendordecolua Affected before 0.5.6 Fixed in 0.5.6 Patch available CNA
  • 9router (npm) Vendor— Affected before 0.5.8 Fixed in 0.5.8 Patch available GHSA-5mj8-gf6m-fhw8

Remediation

  • Fix · CNA 9router (decolua) Fixed in 0.5.6
  • Fix · GHSA-5mj8-gf6m-fhw8 9router (npm) Fixed in 0.5.8 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-56681
  2. 2026-10-03 Alias added: GHSA-5mj8-gf6m-fhw8

References

Other 4

  • TI-2026-36526 9Router: Hardcoded Default fallback JWT Secret Allows Authentication Bypass CVSS 3.1CRITICAL 9.8
  • TI-2026-34059 9Router: Unauthenticated Remote Code Execution via unprotected MCP custom plugin routes CVSS 3.1CRITICAL 10.0
  • TI-2026-44499 9Router 0.4.41 - Unauthenticated API Key Exposure via /api/usage/stats CVSS 4.0CRITICAL 9.3
  • TI-2026-42622 9Router 0.4.41 - Unauthenticated API Exposure via /api/providers CVSS 4.0CRITICAL 9.3
  • TI-2026-44500 9Router 0.4.41 - Unauthenticated Information Disclosure via API Usage Endpoints CVSS 4.0HIGH 8.7
  • TI-2026-40860 9Router: Authenticated Server-Side Request Forgery (SSRF) via OIDC Provider Test Endpoint CVSS 3.1HIGH 8.6
See all 25 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences