CVE-2026-111770highCWE-362

CVE-2026-111770: fallo de gravedad alta en @modelcontextprotocol server

Model Context Protocol TypeScript SDK: Shared transport or server instances delivered one HTTP client's messages to another

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41Vexday Risk Score

Sin señal de explotación. Ella tiene prueba de concepto pública.

ssvc Attendcvss 7.7epss 0.4%
de la publicación al armael mismo día
Publicada en NVD5 nov
1ª PoC21 oct
The Model Context Protocol TypeScript SDK provides TypeScript client and server implementations of the Model Context Protocol. From 2.0.0 until 2.3.0 in @modelcontextprotocol/server, applications that shared one stateless HTTP transport or one McpServer or Server instance among multiple clients could deliver responses and notifications to the wrong client. The affected surface is an MCP server reached over HTTP by multiple clients. The trigger is reuse of one stateless transport or server instance. Messages were associated with a connection using only the JSON-RPC request identifier. SDK clients start request identifiers at zero, so collisions occur in normal operation. Cross-client delivery exposes one client's responses and notifications to another client. The issue requires an HTTP endpoint reachable by more than one client and an application that constructs the server or transport once at startup instead of once per request or session. stdio servers and factory-created per-call servers are not affected. Upgrading causes reused instances to fail and therefore requires an application code change. This issue is fixed in @modelcontextprotocol/server 2.3.0.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H
Productos afectados
@modelcontextprotocol · servermodelcontextprotocol · typescript-sdk
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