Qubic halts chain after attacker drains 1,400 wallets via weak seeds

What happened

Qubic halted its layer-1 blockchain after an attacker exploited weakly generated wallet seeds to drain approximately $1.4 million from more than 1,400 accounts, according to the project. The network was stopped at tick 85,371,949 and remained paused at the time of reporting. Qubic said 2.94 trillion Qubit (QU) was stolen.

Qubic tied the flaw to seeds created with insufficient randomness. Affected wallets included seeds made through any browser on an iPhone or iPad before Oct. 18, 2026, Safari on a Mac before the same date, and the Qubic iOS app before July 2025. The project said the problem came from its wallet software, not the blockchain protocol.

Qubic said 87.1% of the drained funds never left the network and stay frozen in place. The remaining 12.9% was sent to MEXC, whose team froze the receiving account within about an hour.

Qubic said it fixed the seed-generation flaw in web wallet version 4.26.4. A GitHub commit shows the project replaced JavaScript's Math.random() with crypto.getRandomValues() when creating wallet seeds.

Why it matters

The halt leaves most stolen tokens frozen while the core team identifies affected wallets and prepares recovery options. A vote by the network's Computors will decide what happens to the frozen funds, and Qubic has not announced when the chain will restart.

The incident follows other attacks tied to weak wallet seeds. In July, Coldcard disclosed that attackers had stolen funds from wallets whose seeds were weakened by a firmware bug, and similar flaws affected Trust Wallet's browser extension and the Libbitcoin Explorer tool in 2023.

Hacks and exploits made up 19% of crypto crime cases but 40% of reported losses in the third quarter, according to AMLBot's 2026 investigations report covering 250 investigations opened since the start of the year.

What the data shows

Qubic's token had a market capitalization of about $62.6 million at the time of writing, according to CoinGecko. Based on Qubic's reported figures, approximately 2.56 trillion QU remained onchain.

What is still unclear

• Qubic has not established that recovery phrases created under the vulnerable software are secure, and it has not announced when the network will restart.
• The project said it would publish a full technical report after a recovery plan is settled.

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