CVE-2026-42559
Description
A flaw was found in rmcp, the official Rust SDK for the Model Context Protocol. The Streamable HTTP server transport in rmcp failed to validate the incoming Host header, enabling a malicious public website to exploit this through a DNS rebinding attack. This allows the attacker to send authenticated requests to an MCP server operating on the victim's local or private network, potentially leading to unauthorized access to sensitive information or the manipulation of data and services.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Understanding the Weakness (CWE)
Access Control,Other
Technical Impact: Gain Privileges or Assume Identity; Varies by Context
An attacker can access any functionality that is inadvertently accessible to the source.
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