Zano has rolled back approximately one month of blockchain history and relaunched the network at block 3,833,000—just before Hard Fork 6, which introduced Gateway Addresses—following a vulnerability that allowed unauthorized ZANO and Freedom Dollar (fUSD) to enter circulation.

To restore the network, nodes, miners, stakers, exchanges, and other services are required to install an update. The rollback cancels not only unauthorized tokens but also legitimate transactions from the rollback period: transactions from that time will not appear in the restored chain and may require reconciliation. Payments that have already been finalized on other blockchains cannot be reversed. The team stated that it is considering potential losses and will prepare a process for compensation and claims.

The rollback costs a month of history but restores supply

"Doing nothing would have meant unlimited circulation of unauthorized ZANO and fUSD, diluting holders’ shares and breaking the core promise—a fixed supply... That would tell every future attacker that exploited coins retain value. No project would survive that," said Zano Head of Marketing and Growth Quinten van Velzen. He added: "Relaunching the chain before Hard Fork 6 costs us a month of history and trust that we now have to regain. But it restores the supply everyone expected and gives us a path to recovery."

The vulnerability is linked to Gateway Addresses

Zano confirmed that the issue arose from Gateway Addresses—a feature designed to simplify integration for bridges, exchanges, and payment services by managing funds as a single balance using an account-based model. Previously, standard Zano wallets operated on a UTXO model, requiring services to scan the blockchain, track incoming payments, and select outputs for spending.

Private L1 with support for custom assets

Zano launched in May 2019 as an L1 blockchain focused on private payments: standard transactions conceal senders, recipients, amounts, and asset types. In addition to its native ZANO token, the network supports the issuance of custom digital assets; Freedom Dollar (fUSD) is one such token.