“Blockchain immutability has proven to be conditional, not absolute,” experts concluded after an emergency reorganization of 13 blocks in the Litecoin network. The incident was caused by a zero-day attack targeting a vulnerability in the MWEB privacy feature, which forced developers to take extreme measures and effectively rewrite the transaction history of the last two and a half hours.

Moreover, the main reason for the attack’s success was the use of outdated software on many network nodes. Due to the lack of a mandatory update mechanism, miners and exchanges operated under different consensus rules, creating a “two-tier” system where invalid transactions were accepted by part of the network.

As experts stated, “This incident calls into question the trust in transaction finality: if a single bug can erase 13 blocks, then even the standard six confirmations no longer guarantee security.” However, analysts further specified that although the technical issue has been resolved, Litecoin’s reputation has suffered, and the question of how well decentralized networks are protected from coordinated rollbacks remains open.