RMCP: Unauthenticated permanent session-table leak in rmcp Streamable HTTP server transport leads to remote denial-of-service

Summary An unauthenticated remote attacker can leak one entry per HTTP request out of the in-memory session table of LocalSessionManager by sending a well-formed JSON-RPC POST that is not an InitializeRequest. The Streamable HTTP server's handlepost allocates the session before it validates the...

CVE-2026-63128

A flaw was found in rmcp, a Rust SDK for the Model Context Protocol. An unauthenticated remote attacker can send specially crafted JSON-RPC POST requests to the stateful Streamable HTTP server. These requests cause the server to create and permanently retain session and channel state without prop...

CVE-2026-63128

RMCP , the official Rust SDK for the Model Context Protocol, has an unauthenticated denial-of-service vulnerability in its stateful Streamable HTTP server (crates/rmcp/src/transport/streamable_http_server/tower.rs). Prior to version 2.0.0 , StreamableHttpService::handle_post calls LocalSessionMan...

CVE-2026-63128 RMCP: Unauthenticated permanent session-table leak in rmcp Streamable HTTP server transport leads to remote denial-of-service

RMCP is an official Rust SDK for the Model Context Protocol. Prior to 2.0.0, the rmcp crate's stateful Streamable HTTP server in crates/rmcp/src/transport/streamablehttpserver/tower.rs allows an unauthenticated client to send a well-formed JSON-RPC POST that is not an initialization request, or a...