Harmony's answer to a forged 4 billion ONE: delete 109,441 confirmed transactions
The layer-1 will rewind both shards to an Aug. 11 checkpoint and ship a client that rejects the exploit's blocks. Finality on Harmony is now whatever the team decides to keep.
The Investor · Invest desk
What happened
- Harmony laid out a rollback plan to restore its blockchain to blocks timestamped 2026-08-11 23:25:37 UTC.
- The restoration will wipe out the effects of an unauthorized mint of roughly 4 billion ONE.
- All legitimate activity that took place after the stipulated time will be erased alongside the fraud, including buys, sells and transfers made by users.
- The discarded window includes 109,126 regular transactions and 315 staking transactions.
- Harmony said Monday that validators would revert to blocks recorded at 11:25 pm UTC on Aug. 11, with new blocks produced from the next heights using replacement databases.
Why it matters
Harmony has published a plan to rewind its chain to blocks timestamped 2026-08-11 23:25:37 UTC, erasing an unauthorized mint of roughly 4 billion ONE and, with it, everything users confirmed afterwards [1][28][2]. The collateral list is 109,126 regular transactions and 315 staking transactions, or 109,441 confirmations that were settled until the team decided otherwise [3][19].
The mechanics are specific. Harmony says the first forged tokens appeared on Shard 0 in block 92,730,036 [5]; the plan rewinds shard 0 to block 92,730,034 and shard 1 to 94,978,278 using replacement databases, with new blocks produced from heights 92,730,035 and 94,978,279 [8][4][7]. A new client, v2026.1.2, refuses the block hashes tied to the exploit [20]. One checkpointed block was never attacked and is being rolled back anyway, which Harmony frames as preventing future problems [6].
Every alternative was considered and discarded, and the reasoning is internally consistent. A targeted burn was rejected because the forged ONE had already reached exchanges, trading pools and smart contracts, so burning risked confiscating money belonging to third parties [9]. A blacklist was rejected because it leaves the fake supply in the system, a token migration for user disruption, and selective replay was called unworkable [10]. Harmony said selectively restoring transactions was unsafe because balances, contract states and nonces would differ on the replacement chain [12], and warned that using the built-in revert tool could leave residual data and another failure [11]. An independent security firm reviewed the incident and agreed with the rollback, according to Harmony's report [14]. Read the list again: every option that preserved finality also preserved the fraud somewhere. The one chosen preserves neither, and pushes the cost onto users who did nothing.
The sums involved are small relative to the precedent being set. The forged mint was about 26% of supply [29], ONE trades near $0.0007 [17], and market capitalisation is roughly $10.8 million on CoinGecko data [18], which puts the nominal value of the fake tokens around $2.8 million [25]. Those two figures are at least mutually consistent, both implying a supply near 15.4 billion [24]. The transfer numbers are not: Harmony reports the attacker attempting 534 payments of 5 billion tokens each in 106 seconds, of which 477 landed, moving 2,385,000,000,000 ONE [30], roughly 596 times the size of the mint it is supposed to have come from [31]. The report does not reconcile that.
Cause, per on-chain analyst Juiceberg, was a flaw in cross-shard receipt verification that allowed a valid receipt to be processed more than once [15]. Harmony's Aug. 13 update describes crediting a shard without a matching debit inside empty, zero-gas blocks, with a second pre-staking quorum bug possibly involved [16]. This is the same network that accidentally minted 146.28 million ONE through a staking bug in December 2023, roughly 27 times smaller than this event [21][27], and that lost about $100 million from its Horizon bridge in June 2022 in a theft the FBI attributed to Lazarus Group [22].
Watch whether validators actually run v2026.1.2, since the checkpoint only binds the chain if they do [20][4]. Watch the recovery track: investigators say nearly all forged ONE has been traced to wallets or service boundaries, with exchanges, bridges and law enforcement engaged [13]. Neither report describes any compensation for holders whose legitimate transactions get discarded [26]. And watch Ravencoin, facing a potential three-day reorganisation after a consensus flaw, with pools controlling most of its hash rate building a competing chain [23].
Information, not investment advice. This story is general information about companies and markets, drawn from cited reporting. It is not a recommendation to buy, sell or hold any security; check the cited sources before acting.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence60
- Adoption
- Not scored
- Hype gap+20
- Incentives60
- Confidence55
Perspective Coverage
3 publishers- Builder
- Builder 33%
- Operator
- Operator 35%
- Investor
- Investor 32%
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Harmony laid out a rollback plan to restore its blockchain to blocks timestamped 2026-08-11 23:25:37 UTC.
- [2]
All legitimate activity that took place after the stipulated time will be erased alongside the fraud, including buys, sells and transfers made by users.
- [3]
The discarded window includes 109,126 regular transactions and 315 staking transactions.
- [4]
Harmony said Monday that validators would revert to blocks recorded at 11:25 pm UTC on Aug. 11, with new blocks produced from the next heights using replacement databases.
- [5]
Harmony chose the checkpoint time because the first fake tokens appeared in the very next block on Shard 0, block number 92,730,036.
- [6]
Block number 92,730,034 was never attacked, but is being rolled back at the same time to prevent any future problems.
- [7]
The network will start creating new blocks from heights 92,730,035 and 94,978,279.
- [8]
Harmony's stated plan is to rewind shard 0 to block 92,730,034 and shard 1 to block 94,978,278, both at 2026-08-11 23:25:37 UTC, using replacement databases.
- [9]
A targeted burn was considered first but rejected because the fake ONE had already been sent to exchanges, trading pools and smart contracts, so burning could have taken money belonging to innocent people.
- [10]
Harmony rejected a blacklist because it would leave the fake supply in the system, called selectively replaying transactions unworkable because chain state had changed, and rejected a full token migration as too disruptive for users.
- [11]
Using the built-in revert tool to move the chain head was warned against because it could leave behind unwanted data that might lead to another failure.
- [12]
Harmony said selectively restoring transactions was unsafe because balances, contract states, nonces and other conditions would differ on the replacement chain.
- [13]
Harmony said investigators had traced nearly all of the forged ONE to wallets or service boundaries and were working with exchanges, bridges and law enforcement.
- [14]
Harmony's report states that an independent security firm reviewed the hack and agreed with the rollback solution.
- [15]
The hack was first noticed by on-chain analyst Juiceberg, who estimated the attacker used a flaw in how the network checks cross-shard receipts to process the same receipt more than once, creating tokens out of thin air.
- [16]
According to Harmony's August 13 update, a flaw in cross-shard receipt verification let valid receipts be reused, crediting a shard without a matching debit and inflating native ONE inside empty, zero-gas blocks, with a second pre-staking quorum bug possibly involved.
- [17]
After the attack was made public the ONE price fell and is currently around $0.0007.
- [18]
At last look the token had a market cap of roughly $10.8 million, according to CoinGecko data.
- [19]
The discarded window totals 109,441 confirmed transactions.
- [20]
Harmony's new client software, v2026.1.2, will refuse to accept the block hashes tied to the hack.
- [21]
In December 2023 a bug in Harmony's staking system created 146.28 million ONE tokens by accident, forcing a network update.
- [22]
Harmony's Horizon bridge lost about $100 million in a June 2022 theft that the FBI attributed to North Korea's Lazarus Group.
- [23]
Ravencoin faced a potential three-day blockchain reorganization after a consensus flaw was exploited, with mining pools controlling most of its hash rate building a competing chain that could reverse previously confirmed transactions.
- [24]
The 26%-of-supply figure and the market cap divided by price both imply a ONE supply near 15.4 billion, so the two disclosures are mutually consistent.
- [25]
The forged 4 billion ONE is worth roughly $2.8 million at the current price.
- [26]
Neither the Cryptopolitan nor the Cointelegraph account describes any compensation or restitution mechanism for users whose legitimate confirmed transactions are discarded.
- [27]
The 2026 forged mint is roughly 27 times larger than Harmony's accidental December 2023 mint.
- [28]
The restoration will wipe out the effects of an unauthorized mint of roughly 4 billion ONE.
- [29]
Roughly 4 billion ONE, about 26% of the token's supply, was conjured through empty blocks.
- [30]
The hacker tried to send 534 payments of 5 billion tokens each in 106 seconds; 477 went through, moving 2,385,000,000,000 ONE.
- [31]
The 2,385,000,000,000 ONE reported as moved is about 596 times the roughly 4 billion ONE reported as minted.
Sources
3 independent publishers whose own reporting we read for this story.
- cointelegraph.comHarmony plans rollback, wiping 109,000 transactions after ONE exploit
1 article · August 17, 2026
- crowdfundinsider.comHarmony Protocol Plans Network Rollback After Token Forgery Exploit, Raising Blockchain Immutability and Lack of Decentralization Concerns
1 article · August 18, 2026
- cryptopolitan.comHarmony Protocol moves to reverse downtrend with rollback plan announcement
1 article · August 17, 2026
Topics and entities
Topics
- Blockchain rollbacks
- Crypto protocol exploits
- Sharded blockchains