Zano rolls back blockchain after unauthorized creation of about 36.9M ZANO

Zano has rolled back its blockchain after a Gateway Address vulnerability was exploited twice, resulting in the creation of approximately 36.9 million unauthorized ZANO, according to reporting on the incident and the project’s recovery notices.

The reported incidents occurred on August 29 and September 25, 2026. Approximately 18.4 million ZANO was created in each event, bringing the total to about 36.9 million unauthorized coins.

Zano said the unauthorized coins could not be distinguished from legitimate ZANO. The project therefore restarted the chain from block height 3,833,000, immediately before Hard Fork 6, reversing roughly one month of chain history.

Why Zano chose a rollback

The recovery decision centered on the inability to separate the unauthorized ZANO from coins issued legitimately. In that situation, removing only the exploit-related balances was not presented as a viable remedy.

Restarting from block 3,833,000 removed the affected portion of the chain and returned the network to a point immediately before Hard Fork 6. The action affected approximately one month of blockchain history.

A rollback is a significant network intervention because transactions recorded after the selected block are no longer part of the restarted chain. Zano’s notices frame the measure as part of its response to the Gateway Address vulnerability.

Emergency release included HF7 changes

Zano’s emergency release confirmed that it addressed an attack affecting ZANO and assets. The release also incorporated the blockchain rollback and protocol changes associated with Hard Fork 7.

The official notices establish the rollback and the related HF7 changes. Reporting that attributes the two issuance events to an attacker describes the scale and dates of the unauthorized creation, while the project’s own recovery materials provide the basis for the chain restart details.

The incident highlights the operational difficulty created when unauthorized assets cannot be reliably differentiated from valid holdings. In this case, Zano’s selected recovery path was to revert the chain rather than attempt a targeted removal of the newly created coins.

Broader context for blockchain recovery decisions

Network upgrades and protocol changes can alter how blockchain systems process transactions and maintain state. Zano’s HF7-related emergency update followed a recovery decision tied to a specific vulnerability and its effects on the chain.

Other networks continue to make protocol-level changes for different reasons, including performance and transaction design. Readers can also review coverage of Solana bringing Transaction V1, lower rent and 250ms slots to mainnet and Solana reports effects of its 250ms slot-time target.

The available evidence does not establish the identity of the party behind the exploit. It does establish that Zano treated the two unauthorized issuance events as severe enough to restart the blockchain from an earlier height.

Continue reading: Solana bringing Transaction V1, lower rent and 250ms slots to mainnet on BTCNews.

Continue reading: Solana reports effects of its 250ms slot-time target on BTCNews.

Sources

• Cointelegraph: Zano exploiter created 36.9M unauthorized ZANO before blockchain rollback
• Zano Forum / Zano Team: Zano network update: Recovery solution for Gateway Address vulnerability
• Zano GitHub: Zano emergency release

Our creator. Creates amazing NFT collections! Support the editor - Bitcoin_Man(TON) / Bitcoin Man Stickers(TON) / BM Numbers (TON) / Comics Book (TON) / Bitcoin_Man (ETH)

Pi Network (Guide)is a new digital currency developed by Stanford PhDs with over 55 million participants worldwide. To get your Pi, follow this link https://minepi.com/Tsybko and use my username (Tsybko) as the invite code.

Binance: Use this link to sign up and get $100 free and 10% off your first months Binance Futures fees (Terms and Conditions).

Bitget: Use this link Use the Rewards Center and win up to 5027 USDT!(Review)

Bybit: Use this link (all possible discounts on commissions and bonuses up to $30,030 included) If you register through the application, then at the time of registration simply enter in the reference: WB8XZ4 - (manual)