Binance says roughly $6.3 billion in crypto was impacted by a major hack, and that affected user losses will be covered. The exchange put the figure out on October 30, 2026, and it was relayed by market trackers including CoinMarketCap and WatcherGuru. Blockchain security firm Blockaid tied the breach to a malicious EIP-7702 authorization: of 50 signature attempts aimed at a Binance wallet, one succeeded and handed the attacker control.
That single successful signature is the whole story. It explains how a technically modern feature, meant to make wallets more flexible, became the opening for one of the larger reported losses of the year.
The authorization that handed over control
EIP-7702 is an Ethereum account-abstraction standard. It lets an ordinary wallet address temporarily delegate its behavior to a smart contract by signing an authorization message. Used as designed, it powers conveniences such as gas sponsorship, batched actions, and session keys that make holding your own keys less clumsy.
The same mechanism cuts the other way when the signature is malicious. A single signed authorization can point a wallet's code at a contract the attacker controls, and that contract can then move funds. There is no second confirmation screen to catch it after the fact. The authorization is the confirmation.
Blockaid's account is that the attacker did not get lucky on the first try. It describes 50 authorization attempts against a Binance wallet, of which 49 failed and one went through. That ratio matters. It suggests the exchange's defenses were stopping the overwhelming majority of malicious signatures, and that the loss came from the one that slipped past rather than a wide-open door. (This is Blockaid's reading of the on-chain trail, not a Binance post-mortem.)
A $6.3 billion tab Binance says it will cover
Binance's estimate of the total impact is about $6.3 billion, and the exchange has said users will be made whole. A pledge like that is only as good as the balance sheet behind it. Covering a multibillion-dollar shortfall out of corporate funds is the kind of promise that separates exchanges with deep reserves from those running thin.
For customers, the reimbursement commitment is the part that matters most in the short term. It does not change the underlying fact that the funds sat in wallets the exchange controlled, and that the exchange, not the user, was the point of failure.
Majors slid, BNB more than most
Crypto majors were already soft as the disclosure spread. As of October 30, 2026, Bitcoin traded near $77,276, down 3.2% on the day. Ether was around $2,208, off 4.2%. BNB, the token tied most directly to Binance's ecosystem, sat near $710.80, down 4.7%, a slightly steeper drop than the broad market. The Fear and Greed Index read 36, squarely in "Fear."
It is hard to isolate how much of that move reflects the hack versus a broader risk-off session, since equities were sliding on the same day. BNB's underperformance against Bitcoin and Ether is the cleanest market tell that traders priced in something Binance-specific.
Custody is the real exposure
The uncomfortable lesson sits one level below the technical details. Most crypto cards, including Binance's own card program, draw from balances held on the issuing platform. That is convenient, and it means your spending power is only as safe as the custodian's security.
Cards that spend from your own wallet move that risk onto you instead. There is no central honeypot for an attacker to drain in one shot, but also no one obligated to reimburse you if you sign a bad authorization yourself. EIP-7702 is a reminder that self-custody and exchange custody fail in different ways: one fails when the platform is breached, the other when the user is tricked into signing. Neither is immune, and the $6.3 billion figure is what the first kind of failure can cost at scale. For a side-by-side look at how different programs handle this trade-off, the crypto card comparison lays out the custody models.
Overview
Binance disclosed a security breach it estimates at about $6.3 billion and committed to covering affected user losses. Blockaid attributed the hack to EIP-7702, reporting that one of 50 malicious authorization signatures succeeded and gave the attacker control of a Binance wallet. Markets were already weak, with BNB down 4.7% and the Fear and Greed Index at 36 as of October 30, 2026. The episode is a concrete case of custodial risk: the mechanism that makes modern wallets flexible is the same one that, signed in the wrong place, can empty them.
