RUSTSEC-2026-0189 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...

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...