highCVSS 8.6Vulnerability

CVE-2026-56677

### Summary A Server-Side Request Forgery (SSRF) vulnerability exists in the 9Router dashboard via the `/api/auth/oidc/test` endpoint. The application accepts a user-controlled URL string through the `issuerUrl` parameter and performs an outbound HTTP request without validating if the destination IP belongs to a restricted internal network range. Notably, this endpoint can be accessed without active session authentication (Unauthenticated), allowing any remote actor with network visibility to the dashboard API endpoints to trigger outbound infrastructure connections. Depending on the state and response of the internal port targeted, this flaw exhibits two distinct behaviors: 1. **Port Scanning / Blind SSRF (Non-OIDC structures):** Probing internal ports that are closed or running non-HTTP/non-OIDC services (e.g., SSH, Databases) forces predictable application behavior changes (e.g., structural timeout or clear JSON parsing error messages like "Unexpected token..."), allowing internal network reconnaissance. 2. **Full Data Feed Manipulation (OIDC matching structures):** If the targeted internal service responds with a valid OpenID configuration document structure, the backend successfully processes, parses, and reflects the internal properties back to the client, confirming partial data control. --- ### Vulnerable Code Details - **Classification:** VE-Class 4 — OIDC SSRF via issuerUrl (Unauthenticated) - **File Path:** `src/app/api/auth/oidc/test/route.js` - **Vulnerable Logic:** The endpoint accepts the parameter directly from the client request and passes it directly into the network client routine without prior sanitization or middleware authentication wrapper checks. ```javascript // Vulnerable implementation wrapper inside the route handler const discovery = await fetchOidcDiscovery(issuerUrl); // Behind the scenes, this executes a direct dynamic outbound request: // -> fetch(`${issuerUrl}/.well-known/openid-configuration`) ``` An unauthenticated user c

Properties

ghsa_id
GHSA-8g4w-4ffg-8vgx
severity
high
summary
9Router: Authenticated Server-Side Request Forgery (SSRF) via OIDC Provider Test Endpoint
cvss_score
8.6
cve_id
CVE-2026-56677
cvss_vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
is_ghsa_only
false
ghsa_published
2026-08-17T21:58:43Z
source_url
https://github.com/advisories/GHSA-8g4w-4ffg-8vgx
ghsa_updated
2026-08-17T21:58:44Z

Related Entities (5)

VULNERABLE_TO (1)

[Software]npm/9router

AFFECTS (1)

[Software]npm/9router

HAS_WEAKNESS (2)

[Weakness]Server-Side Request Forgery (SSRF)
[Weakness]Missing Authentication for Critical Function

REPORTED_BY (1)

[Source]GitHub Advisory Database

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CVE-2026-56677 (CVSS 8.6) — Ninja Signal Threat Intelligence | Ninja Signal