
Find real vulnerabilities before they ship
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/streamable_http_server/) 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 on the victim's loopback or private-network interface. This vulnerability is fixed in 1.4.0.
Base Score
8.8| Package (Ecosystem) | Introduced | Fixed | Limit |
|---|---|---|---|
| rmcp(crates.io) | 0 | 1.4.0 | N/A |
| Base Score | 8.8 |
|---|---|
| Vector String | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| Base Severity | High |
| Version | 3.1 |
| Attack Vector (AV) | NETWORK |