Ravencoin is facing a potential rollback of four days of transactions after attackers exploited a critical software flaw that allowed invalid blocks to enter the blockchain starting August 7. Two major mining pools controlling most of the network's computing power are rebuilding the blockchain from before the first bad block, risking erasure of recent payments and causing exchanges like Bitvavo and Upbit to halt deposits and withdrawals. The project has patched the flaw but cannot undo the invalid blocks already added. This situation leaves control of the blockchain's recent history in the hands of these mining pools, creating uncertainty for users and exchanges until the network settles on a single version of the chain.
