Bitcoin Lightning Network, a solution designed to speed up transactions on the Bitcoin blockchain, has been found to have a major vulnerability. The flaw, known as "replacement cycling attacks," could allow attackers to disrupt the normal flow of transactions and potentially cause loss of funds within the network's channels.

While no real-world attacks have been reported, the vulnerability could impact other Bitcoin protocols and applications. The developer who discovered the flaw has ceased work on Lightning and its implementations, citing security concerns. Mitigation steps have been taken, but their effectiveness against advanced forms of the attack is uncertain.