ETK-2026-1686Zero's internal tracking ID, independent of the CVE number.

{
  "etk_id": "ETK-2026-1686",
  "cve_id": null,
  "display_id": "ETK-2026-1686",
  "ghsa_id": "GHSA-f897-62hf-6gxq",
  "euvd_id": null,
  "status": "published",
  "anchor_state": "awaiting_cve",
  "title": "HTTP request resource exhaustion in MCP server packages",
  "summary": "MCP servers using Streamable HTTP with affected MCP packages can accept unbounded POST bodies and JSON-RPC batches. An unauthenticated attacker who can reach the endpoint may exhaust memory or prevent other clients from being served; stdio-only servers are not affected.",
  "mitigation": "Upgrade installed packages to @modelcontextprotocol/sdk 1.30.1 or later, @modelcontextprotocol/server and @modelcontextprotocol/node 2.1.0 or later, and @modelcontextprotocol/hono 2.0.1 or later. Until upgraded, enforce a request-body size cap at a reverse proxy.",
  "vendor": "npm",
  "product": "npm:@modelcontextprotocol/sdk",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 1.10.0, < 1.30.1"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "1.30.1"
      ],
      "package_name": "@modelcontextprotocol/sdk",
      "purl": "pkg:npm/@modelcontextprotocol/sdk"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 2.0.0, < 2.1.0"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "2.1.0"
      ],
      "package_name": "@modelcontextprotocol/server",
      "purl": "pkg:npm/@modelcontextprotocol/server"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 2.0.0, < 2.1.0"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "2.1.0"
      ],
      "package_name": "@modelcontextprotocol/node",
      "purl": "pkg:npm/@modelcontextprotocol/node"
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 2.0.0, < 2.0.1"
      ],
      "ecosystem": "npm",
      "fixed_versions": [
        "2.0.1"
      ],
      "package_name": "@modelcontextprotocol/hono",
      "purl": "pkg:npm/@modelcontextprotocol/hono"
    }
  ],
  "cwes": [
    770
  ],
  "cvss_score": 7.5,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss_score": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "contextual",
  "check": true,
  "check_confidence_basis": "assessed",
  "exploit": false,
  "pipeline_minutes": 15.538209766666666,
  "t0_at": null,
  "signals": {
    "check": {
      "at": "2026-10-15T14:59:39.858221+00:00",
      "days": -6.062457007743055,
      "is_lower_bound": true,
      "measured_at": "2026-10-21T16:29:36.294631+00:00",
      "url": null
    },
    "trigger_signal": {
      "at": "2026-10-15T13:10:21+00:00",
      "days": -6.13836971863426,
      "is_lower_bound": true,
      "measured_at": "2026-10-21T16:29:36.294631+00:00",
      "url": "https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-f897-62hf-6gxq"
    }
  }
}