js-libp2p: Memory DoS via subscription flood of unique topics
Three cooperating omissions in @libp2p/gossipsub allow an unauthenticated single peer to exhaust the Node.js heap of any gossipsub node with default options. defaultDecodeRpcLimits.maxSubscriptions = Infinity (packages/gossipsub/src/message/decodeRpc.ts:11): no decode-level cap on subscription entries per RPC. handleReceivedSubscription is unbounded (gossipsub.ts:1009-1021): every unique topic string creates a new Map entry + Set object in this.topics with no per-peer count limit. removePeer leaves empty Sets (gossipsub.ts:782-784): after peer disconnect, empty Sets are never deleted …