CVE-2026-67431

The CVE affects the MCP Ruby SDK (Model Context Protocol) prior to version 0.23.0. In MCP::Server::Transports::StreamableHTTPTransport, the session ID is not bound to a session owner, allowing a stolen session ID to cause requests (tools/call) to execute in the victim’s session. This is fixed in ...

CVE-2026-67430 MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood

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 expire sessions by default, so repeated initialize requests retain unbounded ServerSession objects and can exhaust proces...

CVE-2026-67430 MCP Ruby SDK: Unbounded session retention in StreamableHTTPTransport allows memory exhaustion via initialize flood

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 expire sessions by default, so repeated initialize requests retain unbounded ServerSession objects and can exhaust proces...

CVE-2026-63118 MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection

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 validate the HTTP Host or Origin request headers, which allows a malicious browser page to use DNS rebinding to reach a...

EUVD-2026-49934

The terraform-mcp-server before version 1.1.0 is vulnerable to a server-side request forgery issue in the streamable-HTTP transport that may allow an unauthenticated remote client to redirect the server's Terraform API requests, and the server-side authorization token, to an attacker-controlled...

CVE-2026-14869: Server-Side Request Forgery (SSRF)

The terraform-mcp-server before version 1.1.0 is vulnerable to a server-side request forgery issue in the streamable-HTTP transport that may allow an unauthenticated remote client to redirect the server's Terraform API requests, and the server-side authorization token, to an attacker-controlled...

Unbounded JSON-RPC request body causes uncontrolled memory allocation in StreamableHTTPTransport

Summary An unauthenticated remote attacker can force any MCP Ruby SDK server using MCP::Server::Transports::StreamableHTTPTransport to allocate gigabytes of memory by sending a single oversized JSON-RPC POST. The transport reads the entire HTTP body into a Ruby String and parses it with...

CVE-2026-50287: Missing Authentication for Critical Function

AgenticMail gives AI agents real email addresses and phone numbers. Prior to version 0.9.27, @agenticmail/mcp exposes a Streamable HTTP transport when started with --http or MCPHTTP=1. In that mode, the /mcp endpoint accepts requests without any HTTP authentication layer. A remote client can...

CVE-2026-33252: Cross-Site Request Forgery (CSRF)

The Go MCP SDK used Go's standard encoding/json. Prior to version 1.4.1, the Go SDK's Streamable HTTP transport accepted browser-generated cross-site POST requests without validating the Origin header and without requiring Content-Type: application/json. In deployments without Authorization,...

CVE-2026-33252

The Go MCP SDK used Go's standard encoding/json. Prior to version 1.4.1, the Go SDK's Streamable HTTP transport accepted browser-generated cross-site "POST" requests without validating the "Origin" header and without requiring "Content-Type: application/json". In deployments without Authorization...

PT-2026-6350

Summary Cross-client response data leak when a single McpServer/Server and transport instance is reused across multiple client connections, most commonly in stateless StreamableHTTPServerTransport deployments. Impact Who is affected: Any MCP server deployment using the TypeScript SDK where a sing...

CVE-2025-66414

MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. Prior to 1.24.0, The Model Context Protocol MCP TypeScript SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without...