Is Your Blockchain Explorer Safe from Denial-of-Service (DoS) Attacks?

## Executive summary This CertiK article analyzes denial-of-service (DoS) risks in blockchain explorers and exposed node RPCs, demonstrating how unbounded query parameters, nested GraphQL queries, exposed Cosmos RPC endpoints, and long-hanging handlers can exhaust CPU, memory, or connection slots and render services or nodes unresponsive; the report provides impact examples (including a Cosmos node crash), mitigation guidance (rate limiting, input validation, RPC wrappers, hardware recommendations), and a sample PoC DoS script for testing.