Slow Mist Cosine's replacement cycle attack on the Lightning Network stated: This attack is complex to implement, and it is recommended that the project party establish a channel with trusted upstream and downstream. To implement this attack, the following requirements must be met:
Two channels are opened with the victim, the transaction is routed through these two channels, the replacement cycle total is achieved within the Δ block, and the victim does not discover the HTLC prepaid word transaction.
According to previous news, Bitcoin Core core developer /dev/fd0 announced on the X platform that it will stop participating in the development of the Lightning Network and its implementation, including coordinating and handling protocol-level security issues. /dev/fd0 means that each Bitcoin node has its own memory pool. Transactions are forwarded by peer nodes. If an LN node is used to open a channel and accept HTLC forwarding, it is vulnerable to substitution loop attacks.