Description
MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not bind a session ID to a session owner, allowing an attacker with a stolen session ID to send tools/call requests that execute in the victim's session. This issue is fixed in version 0.23.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| modelcontextprotocol | ruby-sdk | < 0.23.0 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| RubyGems | mcp | < 0.23.0 | 0.23.0 | GHSA-5p9g-j988-pcwv |