CVE-2026-63128highCWE-400CWE-401CWE-772

CVE-2026-63128: fallo de gravedad alta en modelcontextprotocol rust-sdk

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

Publicada el

Seguir esta CVE+ Monitorear rust-sdk+ Monitorear rmcp

Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.

21Vexday Risk Score

Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.

ssvc Trackcvss 7.5epss 0.5%
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/streamable_http_server/tower.rs allows an unauthenticated client to send a well-formed JSON-RPC POST that is not an initialization request, or an initialization request with a mismatched protocol header, causing StreamableHttpService::handle_post to call LocalSessionManager.create_session before validating the message. An early validation failure returns without removing the inserted LocalSessionHandle from LocalSessionManager.sessions, permanently retaining session and channel state for the server process lifetime. Repeated requests can grow the shared session table without bound, degrade legitimate-client latency through lock contention, exhaust memory, and terminate the server. This issue is fixed in version 2.0.0.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Productos afectados
modelcontextprotocol · rust-sdk
CVEs relacionadas — modelcontextprotocol rust-sdk

En el mismo producto, de las más peligrosas a las menos.

CVE-2026-64684MEDIUMRMCP: Custom HTTP headers leak to cross-origin redirect targetsEPSS 0.5%CVE-2026-42559HIGHRMCP: DNS rebinding vulnerability in rmcp Streamable HTTP server transportEPSS 0.3%CVE-2026-63127HIGHRMCP: Missing Resource Field Validation in OAuth Protected Resource Metadata DiscoveryEPSS 0.2%