BroadChain learned that at 21:56 on April 26, according to BeInCrypto, the Litecoin network urgently implemented a 13-block reorganization due to a zero-day attack to reverse invalid transactions. This move has reignited market doubts about blockchain transaction finality and network security.
The attack stemmed from incorrect validation of MWEB privacy transactions by unupdated nodes, creating a dual-track consensus rule. Mining pools and exchanges running old software inadvertently provided conditions for the attack. As a relatively new feature, MWEB's complexity increased the attack surface.
Litecoin's hashrate and security budget are relatively low, with the 13-block reorganization covering approximately 2.5 hours of history. In contrast, a reorganization of the same depth on Bitcoin would be extremely costly. The incident exposed the reliance of decentralized networks on coordinated node updates, and transaction finality is not absolute.