RMCP: DNS rebinding vulnerability in rmcp Streamable HTTP server transport
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.8epss 0.2%
exploitation probability
0.2%top 88% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Affected products
modelcontextprotocol · rust-sdkReferences
https://github.com/modelcontextprotocol/rust-sdk/commit/8e22aa2de28df5a285eed87c11cd89bf15fa90d3https://github.com/modelcontextprotocol/rust-sdk/issues/815https://github.com/modelcontextprotocol/rust-sdk/issues/822https://github.com/modelcontextprotocol/rust-sdk/pull/764https://github.com/modelcontextprotocol/rust-sdk/security/advisories/GHSA-89vp-x53w-74fx