CVE-2026-42559

The RMCP Streamable HTTP server transport in the rmcp crate failed to validate the Host header prior to version 1.4.0, enabling a DNS rebinding attack that could cause authenticated requests to reach a victim’s local MCP server. Impact could include enumeration, reading state, and triggering side...

EUVD-2026-30292

RMCP is an official Rust SDK for the Model Context Protocol. Prior to version 1.4.0, the rmcp crate's Streamable HTTP server transport crates/rmcp/src/transport/streamablehttpserver/ did not validate the incoming Host header. This allowed a malicious public website, via a DNS rebinding attack, to...

rmcp Streamable HTTP server transport has a DNS rebinding vulnerability

Summary Prior to version 1.4.0, the rmcp crate's Streamable HTTP server transport crates/rmcp/src/transport/streamablehttpserver/ did not validate the incoming Host header. This allowed a malicious public website, via a DNS rebinding attack, to send authenticated requests to an MCP server running...

GHSA-89VP-X53W-74FX rmcp Streamable HTTP server transport has a DNS rebinding vulnerability

Summary Prior to version 1.4.0, the rmcp crate's Streamable HTTP server transport crates/rmcp/src/transport/streamablehttpserver/ did not validate the incoming Host header. This allowed a malicious public website, via a DNS rebinding attack, to send authenticated requests to an MCP server running...

DNS rebinding vulnerability in rmcp Streamable HTTP server transport

Prior to version 1.4.0, the rmcp crate's Streamable HTTP server transport did not validate the incoming Host header. This allowed a malicious public website, via a DNS rebinding attack, to send requests to an MCP server running on the victim's loopback or private-network interface. An attacker wh...