Three "infinimint" crypto bridge exploits in ten days show cross-chain bridges are crypto's unsolvable security hole — and audits can't save them.
Crypto Bridge Exploits Are a Design Flaw, Not Bad Luck
Key Takeaways
- Three "infinimint" bridge hacks hit in ten days this October: Initia ($2.7M), Cysic ($727K), and Autheo's THEO (~$1.76M).
- Every one followed the same recipe — mint unbacked tokens on one chain, bridge out real assets before anyone reacts.
- Audits didn't help. Autheo had been reviewed by Halborn, CertiK, and Avelar Labs and still got drained.
- A bridge is a minting machine wrapped in code. Code has bugs. That is a design problem, not a streak of bad luck.
- Until bridges are collateralized, insured, or replaced, every bridged token is an unbacked promise.
In the span of ten days this October, three blockchains were robbed with the exact same trick: mint tokens out of thin air, then walk out with the real money. Initia (https://initia.xyz) lost roughly $2.7 million on October 23. Cysic lost about $727,000 on October 17. Autheo (https://autheo.com)'s THEO token was drained for around $1.76 million on October 13. Three different teams, three different codebases, one identical failure. These crypto bridge exploits aren't a run of bad luck. They're a design flaw the industry has spent five years insisting it could engineer its way around.
What actually happened
Initia, a MoveVM-based Layer 1 that runs a network of interwoven rollups, was the biggest hit. An attacker exploited a script-caching bug in its MoveVM — the virtual machine itself, not some hastily written app — to spoof the chain's state and credit themselves with WETH, iUSD, and USDC that no deposit ever backed. Then they bridged out roughly $2.7 million through LayerZero and Noble/CCTP before the chain was halted at 15:41:30 UTC.
The detail that should terrify you: Bitquery, the on-chain analytics firm, found the bridge's USDC reserve fell from about $1.09 million to $63 in a single afternoon. The attacker's fake balances totaled around $7.48 million, but they could only extract about $3 million — because the reserve literally ran dry. The remaining losses landed on honest users whose withdrawals simply stopped clearing. They held IOUs, and the vault behind those IOUs was empty.
Cysic, a zero-knowledge hardware project, was hit on October 17 through a different door — a breached support database combined with a flaw in how the bridge processed "mint" messages. The attacker forged 10 million CYS tokens on BNB Chain and bridged out about 306.6 ETH to Ethereum. The foundation froze 2.8 million tokens and offered a 10% bounty. The attacker declined, then pushed 300 ETH and 30.4 BNB into Tornado Cash.
Autheo was the most cinematic. On October 13, someone minted millions of THEO tokens on Base through a suspected Hyperlane bridge exploit — one researcher put it at 119 million, roughly 70% of supply — swapped them for about 700 ETH, and dumped them. The token cratered in hours. Then the attacker did something strange: they sent roughly $1 million worth of THEO to a random stranger's wallet, a move that looks less like generosity and more like a deliberate attempt to smear an innocent address and muddy attribution.
Why didn't the audits catch this?
The Autheo case is the kill shot against crypto's favorite defense. This project had been reviewed by Halborn, CertiK, and Avelar Labs — three brand-name security firms. It still got drained. That's the whole point. Audits find known bug patterns in known code paths. They don't fix a structurally unsound model. When the vulnerability lives in the virtual machine's caching logic (Initia) or the bridge's message-processing middleware (Cysic, Autheo), no amount of smart-contract review would have caught it. The "we got audited" badge is a marketing asset, not a security guarantee.
The bigger picture: bridges are the load-bearing wall
Zoom out and every one of these attacks shares a single primitive: the mint function. A bridge works by locking real asset A on chain X and minting a receipt on chain Y. That receipt is the bridge's promise. Break the mint — or the logic that decides when minting is allowed — and you can create the promise without ever making the deposit. That's not a novel idea. It's the same economic invariant that banks call solvency risk. The difference is a bank has capital, insurance, and regulators. A bridge has a smart contract and a hope.
This matters because multichain is crypto's stated future, and bridges are its load-bearing wall. Chain abstraction, restaking, the hundreds of new L2s and L3s — they all assume assets can move freely between chains. That movement runs on bridges. And the security pressure isn't easing: Chainalysis (https://www.chainalysis.com) estimates North Korea-linked groups have stolen over $1 billion in 2026 alone, with the September Bitget hack revised upward to $387.5 million. The professional attackers aren't guessing. They've industrialized the hunt for exactly these mint-and-drain bugs.
Who wins and who loses?
The losers are easy to name. Honest users holding bridged assets ate the difference between fake and real balances on Initia. The projects themselves burned months of credibility overnight. And the "audited = safe" narrative took another body blow.
The winners are less obvious. Architectures that don't require bridging — native issuance, intent-based settlement, single-settlement-layer rollups — just got a free sales pitch. Security firms and insurers get a bigger mandate. And the attackers proved, for the third time in ten days, that this is the cheapest high-yield exploit in crypto.
The second-order consequence is quieter but bigger: the "chain abstraction" story — the idea that users shouldn't have to know which chain they're on — now carries a hidden liability. Every layer that hides a bridge from the user also hides the bridge's solvency risk. Abstraction is a UX win and a risk-management nightmare.
Has this happened before?
Yes, and 2022 was the year bridges went to the slaughterhouse: Ronin ($625 million), Wormhole ($325 million), Nomad ($190 million). Chainalysis has long ranked bridges as the single highest-value attack target, and total bridge losses across 2021–2024 ran past $2.5 billion. What's different now is where the attacks land. Ronin was a validator social-engineering job. Wormhole and Nomad were smart-contract logic bugs. Initia was a bug in the virtual machine itself, and Cysic and Autheo were bugs in bridge middleware. The industry patched the top layers of the stack — so the attackers simply went lower, where the code is newer, more complex, and less scrutinized.
Where does this go in the next three years?
Three predictions. First, "infinimint" — minting unbacked tokens and draining the reserve — becomes the default bridge attack, because it requires no key compromise and scales with whatever the bridge holds. Second, bridges get treated like the financial intermediaries they functionally are: expect reserve attestation, proof-of-solvency, and insurance mandates to move from marketing garnish to table stakes, possibly with regulators driving it. Third, the winning architectures stop bridging. Native stablecoin issuance on each chain, intent-based settlement where solvers compete to fill a user's order without a minting bridge in the middle, and rollups that share a base settlement layer will steadily eat the bridge's lunch. Bridging won't die. But it will be demoted from default infrastructure to specialized, collateralized plumbing.
The trader's angle
This isn't about where any token price goes. It's about where your money sits. Treat "assets sitting inside a bridge contract" as its own risk category — separate from the protocol itself. Where liquidity allows, prefer native or directly-issued assets over wrapped and bridged versions, because the wrapped token inherits the solvency of whatever bridge minted it. Watch for projects that post real-time reserve proofs or carry third-party insurance; those are the ones treating a bridge like a bank instead of a smart contract. And note the Autheo "gift" to a random wallet: it's an attribution attack, designed to slow law enforcement and create plausible deniability. Expect more of it.
The bill came due
The next nine-figure crypto hack probably won't be a private-key screwup or a flash-loan oracle manipulation. It'll be someone minting a billion dollars of IOUs through a bridge's mint function and walking out before the reserve empties. The uncomfortable truth is that five years of "audits, audits, audits" haven't closed the hole — because the hole isn't in the code. It's in the concept. We built an entire multichain economy on the assumption that a minting machine could be secured with enough test coverage. October 2026 was the bill coming due. The only question is whether the industry reads the invoice before the next one arrives.
FAQ
What is an "infinimint" bridge exploit? It's an attack where someone mints unlimited unbacked tokens on one chain and bridges them out as real assets. The term comes from on-chain analyst Spreek's description of the Initia hack: the attacker "created bridgeable tokens on Initia without backing and bridged them back out, draining the bridge contract."
Why do cross-chain bridges keep getting hacked? A bridge must mint a receipt token whenever an asset is locked. If an attacker breaks the logic guarding that mint, they can create receipts without deposits and redeem real collateral. That's a solvency failure, not just a security bug — and it's inherent to how bridges work.
Do audits prevent bridge hacks? Not reliably. Autheo had been audited by Halborn, CertiK, and Avelar Labs before its October 2026 exploit and still got drained. Audits catch known bug patterns in reviewed code; they don't fix a structurally unsound model or catch bugs in a virtual machine's caching layer.
Are my bridged assets safe? Any token that crossed a bridge carries that bridge's solvency risk. Native assets don't. Where possible, prefer native or directly-issued assets over wrapped or bridged versions, and favor projects that publish real-time reserve proofs.
What actually fixes this? Native issuance, intent-based settlement, and collateralized or insured bridges — plus treating bridge operators as financial intermediaries subject to reserve attestation. The long-term answer is fewer things to bridge, not better bridges.