Qubic Halts Network After Weak Wallet Seeds Let Attacker Drain 1,400 Accounts

Qubic stopped its layer-1 chain after an attacker reportedly emptied more than 1,400 wallets created with predictable seeds. Most of the stolen QU remains frozen, and a validator vote on recovery is pending, with no restart date announced.

Qubic pauses the chain while it works out who lost what

Qubic halted its network on Sunday after an attacker reportedly took roughly $1.4 million from more than 1,400 accounts, according to Cointelegraph. The project said on X that the chain stopped at tick 85,371,949 and was still paused when Cointelegraph published. The stolen amount was 2.94 trillion Qubit (QU), the network's token.

Qubic says most of the loot never left the network. The project said 87.1% of the drained funds remain frozen in place, while the other 12.9% went to the exchange MEXC. Qubic said the exchange's team locked the account that received those tokens roughly one hour after the transfer.

The Defiant carried the same core claim in a shorter report. It said the drained QU is immobilized on the network and that MEXC froze the account that received the rest.

Why a random-number shortcut can empty a wallet

A wallet seed is the secret from which every key in the wallet is derived. If an attacker can guess how the seed was produced, they can rebuild the keys without ever touching the owner's device. Strong seeds therefore depend on a source of randomness that cannot be predicted.

Cointelegraph pointed to a GitHub commit for version 4.26.4 of the Qubic web wallet. According to that report, the commit swaps JavaScript's Math.random() function for crypto.getRandomValues() when seeds are created. The first function is not suited to generating cryptographic secrets, while the second is built for that purpose.

Qubic told readers which users were exposed. Seeds generated in any browser on an iPhone or iPad were affected, as were seeds created in Safari on a Mac up to Oct. 18, 2026. Seeds from the Qubic iOS app before July 2025 were also in scope. Qubic said it has fixed the flaw in the latest web wallet.

The numbers behind the incident

The reported figures differ slightly between outlets, so the table of facts below follows Cointelegraph's fuller account unless noted.

• Amount taken: about $1.4 million, or 2.94 trillion QU, according to Cointelegraph.
• Accounts affected: more than 1,400.
• Halt point: tick 85,371,949.
• Share still on the Qubic network and frozen: 87.1%.
• Share sent to MEXC and frozen there: 12.9%.
• Time MEXC took to freeze the receiving account: about an hour, per Qubic.
• Fixed wallet release: version 4.26.4.
• Token market capitalization at the time of writing: about $62.6 million, per CoinGecko as cited by Cointelegraph.

Where the two outlets agree and where they diverge

Both outlets relay the same split of funds and the same MEXC freeze, and both attribute those claims to Qubic. The main difference is the dollar value. Cointelegraph put the loss at approximately $1.4 million, while The Defiant's headline gave a somewhat lower dollar figure.

The gap is small, and neither report explains it. A likely reason is a different token price at the moment of conversion, but neither outlet says so, so it remains an open point. The Defiant's piece is available only as a headline and summary, so it adds nothing on the vulnerability, the affected devices or the recovery process.

Cointelegraph supplies the rest of the detail. It reports the tick number, the list of affected platforms, the code change and the plan for a vote. It also notes that Qubic did not immediately respond to its request for comment, so the account so far rests on the project's own statements.

A pattern of weak-seed failures

Cointelegraph described the Qubic case as the latest in a run of attacks tied to poorly generated seeds. Coldcard reported in July that a firmware bug had weakened some wallet seeds, and that attackers had taken funds from the affected wallets. In 2023, similar flaws hit the Trust Wallet browser extension and the Libbitcoin Explorer tool.

The outlet also placed the incident against a wider security backdrop. It linked to its report that Bitget's $388 million hack pushed third-quarter crypto security losses past $1 billion. It further cited AMLBot's 2026 investigations report, which found that hacks and exploits made up 19% of crypto crime cases in the third quarter but 40% of reported losses, based on 250 investigations opened since the start of the year.

Qubic itself is a layer-1 network that supports fee-free transactions and smart contracts. Cointelegraph says it runs on Useful Proof of Work, a consensus design that redirects mining energy toward training artificial intelligence. That design is not reported as a factor in the theft.

What holders and the network have to decide next

According to Qubic, its core team is working to determine which wallets were hit and is drawing up options for getting funds back. Those options will be put to a vote by the network's Computors, and the outcome will determine how the frozen funds are handled. The team also promised a full technical report once a recovery plan is settled.

No restart date has been announced. Users who created a wallet seed on one of the affected platforms can check the creation date and device against the list Qubic published. Teams that ship wallet software can take a more general lesson from the code change, which is to confirm that seed generation relies on a cryptographically secure random source.

Several questions remain open. The outlets do not say how the attacker identified the vulnerable seeds, what the vote will propose, or whether owners of the remaining 12.9% sent to MEXC can recover those funds. Those answers are likely to come in the technical report Qubic has promised.

FAQ

What happened to the Qubic network?

Qubic halted its layer-1 chain at tick 85,371,949 after an attacker reportedly drained about $1.4 million, or 2.94 trillion QU, from more than 1,400 accounts, according to Cointelegraph. The project says the cause was weakly generated wallet seeds. No restart date has been announced.

Which Qubic wallets were affected?

Qubic said seeds generated in any browser on an iPhone or iPad were affected. Seeds created in Safari on a Mac until Oct. 18, 2026 and in the Qubic iOS app before July 2025 were also included. The web wallet flaw is fixed in the latest version.

Can the stolen QU be recovered?

Qubic says 87.1% of the drained funds remain frozen on its network and the rest was sent to MEXC, which froze the receiving account. The network's Computors are due to vote on a recovery plan. The outlets have not reported what that plan will contain.

Sources

• Cointelegraph: Qubic freezes chain after attacker drains 1.4K wallets with weak seeds (2026-10-19)
• The Defiant: Qubic Halts Network After $1.3 Million Wallet Drain (2026-10-18)