Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection

Summary MCP::Server::Transports::StreamableHTTPTransport the Rack-mountable Streamable HTTP transport in the mcp gem processes every incoming JSON-RPC request without ever inspecting the HTTP Host or Origin request headers. There is no AllowedHosts/AllowedOrigins allowlist and no DNS-rebinding...

CVE-2026-59096

Dapr Sentry's OIDC discovery endpoint derives the issuer and jwksuri of the /.well-known/openid-configuration document from the request Host, honoring an attacker-controlled X-Forwarded-Host header without validation when no allowed-hosts list is configured the default, and serves the document wi...