Replacement Cycling Attack Disclosed by Antoine Riard, Oct 2023. A novel mempool-policy attack against Lightning where an attacker repeatedly cycles RBF-replacing their own malicious child tx, forcing your honest fee-bumping attempts to incur progressively higher costs while their tx sits in mempool, eventually causing your legitimate sweep tx (HTLC-timeout) to miss its CLTV deadline. The setup You're routing a payment Alice → You → Bob: - You have an outgoing HTLC to Bob (Bob owes you). - You have an incoming HTLC from Alice (you owe Alice). - Alice's HTLC has earlier CLTV; Bob's HTLC has la…