CVE-2026-34742

The CVE-2026-34742 entry concerns the Model Context Protocol (MCP) Go SDK. Prior to version 1.4.0, an HTTP-based MCP server running on localhost without authentication did not enable DNS rebinding protection by default, allowing a malicious website to bypass same-origin policy and send requests t...

CVE-2026-34742: Initialization of a Resource with an Insecure Default

The Go MCP SDK used Go's standard encoding/json. Prior to version 1.4.0, the Model Context Protocol MCP Go SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without authentication with StreamableHTTPHandler or...

CVE-2026-33252 MCP Go SDK Allows Cross-Site Tool Execution for HTTP Servers without Authorizatrion

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,...

GO-2026-4569 MCP Go SDK Vulnerable to Improper Handling of Case Sensitivity in github.com/modelcontextprotocol/go-sdk

MCP Go SDK Vulnerable to Improper Handling of Case Sensitivity in github.com/modelcontextprotocol/go-sdk...

MCP Go SDK Vulnerable to Improper Handling of Case Sensitivity

The Go MCP SDK used Go's standard encoding/json.Unmarshal for JSON-RPC and MCP protocol message parsing. Go's standard library performs case-insensitive matching of JSON keys to struct field tags — a field tagged json:"method" would also match "Method", "METHOD", etc. Additionally, Go's standard...

CVE-2026-27896 MCP Go SDK Vulnerable to Improper Handling of Case Sensitivity

The Go MCP SDK used Go's standard encoding/json.Unmarshal for JSON-RPC and MCP protocol message parsing in versions prior to 1.3.1. Go's standard library performs case-insensitive matching of JSON keys to struct field tags — a field tagged json:"method" would also match "Method", "METHOD", etc...