{
  "entry": {
    "kind": "vuln",
    "slug": "cve-2026-25536",
    "name": "CVE-2026-25536",
    "vendor": "@modelcontextprotocol/sdk",
    "description": "When a single McpServer instance using StreamableHTTPServerTransport was reused across multiple HTTP clients, a common stateless deployment pattern, response routing could misfire and deliver one client's data to a different client entirely. Affected MCP SDK versions 1.10.0–1.25.3; fixed in 1.26.0. At disclosure, 82% of surveyed production MCP servers were running a vulnerable version.",
    "website": "https://nvd.nist.gov/vuln/detail/CVE-2026-25536",
    "repository": null,
    "documentationUrl": null,
    "license": null,
    "version": null,
    "trustLevel": "advisory",
    "capabilities": [],
    "packaging": {
      "manager": "unknown",
      "packageName": "@modelcontextprotocol/sdk",
      "command": null
    },
    "configFiles": null,
    "category": "mcp-server",
    "updatedAt": "2026-03-18",
    "risk": {
      "score": 75,
      "band": "high",
      "signals": [],
      "dangerousCombos": []
    },
    "dangerousCombos": [],
    "vuln": {
      "id": "CVE-2026-25536",
      "aliases": [
        "ti-003"
      ],
      "title": "CVE-2026-25536: MCP TypeScript SDK Cross-Client Data Leak",
      "summary": "When a single McpServer instance using StreamableHTTPServerTransport was reused across multiple HTTP clients, a common stateless deployment pattern, response routing could misfire and deliver one client's data to a different client entirely. Affected MCP SDK versions 1.10.0–1.25.3; fixed in 1.26.0. At disclosure, 82% of surveyed production MCP servers were running a vulnerable version.",
      "severity": "high",
      "cvss": {
        "score": null,
        "vector": null,
        "version": null
      },
      "cwe": [],
      "attackType": [
        "Information disclosure"
      ],
      "componentType": "mcp-server",
      "component": {
        "name": "@modelcontextprotocol/sdk",
        "vendor": null,
        "package": "@modelcontextprotocol/sdk",
        "ecosystem": null,
        "catalogSlug": null
      },
      "affected": [
        {
          "range": ">=1.10.0 <1.26.0",
          "fixed": "1.26.0"
        }
      ],
      "exploited": false,
      "exploitPublic": false,
      "publishedAt": "2026-03-18",
      "modifiedAt": "2026-03-18",
      "lastVerified": "2026-11-01",
      "references": [
        {
          "type": "cve",
          "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25536"
        }
      ],
      "mitigation": "Upgrade @modelcontextprotocol/sdk to 1.26.0+. If upgrading is not immediate, deploy one McpServer instance per HTTP client (no shared instances). Audit MCP server logs for cross-client response anomalies.",
      "detectedByAnomity": true
    }
  }
}