In May 2026, one of decentralized finance’s top security minds set off alarm bells across the crypto space. Manuel Arios, who co-founded OpenZeppelin and once served as its CTO, told the world he no longer trusts DeFi. Even more startling, he admitted to quietly urging his friends and family to pull their money out of major DeFi protocols.
This wasn’t just a casual critic venting online. Arios practically helped lay the bricks for modern DeFi security — so when someone like that starts sounding the alarm, people listen.
The real question isn’t complicated, though it’s not exactly comfortable: Has artificial intelligence tipped the scales and made DeFi fundamentally unsafe?
If you’ve touched DeFi, you’ve probably relied on OpenZeppelin, even if you didn’t realize it. Their open-source smart contract libraries are everywhere: lending apps, exchanges, tokens — you name it. OpenZeppelin powers things like access controls, governance, token contracts, and security modules. Over the years, their team has unearthed thousands of vulnerabilities and audited hundreds of projects. Their code is one of the gold standards in blockchain development.
That’s why Arios’s warning hits so hard. He has a front-row seat to how all this stuff works — and where it goes wrong.
Arios’ argument comes down to something every security pro knows: defenders have to get everything right. Attackers only need one oversight.
That’s always been true for software, but DeFi cranks the difficulty way up because of three quirks:
Immutable Code
Once a smart contract goes live, changing it is often tough or impossible. If there’s a bug, patching it might not be on the table.
Complete Transparency
Every hacker in the world can pore over every single line of code. You don’t need connections or backdoors — just an internet connection and time.
Everyone Sees the Money
DeFi doesn’t hide the prize. Anyone can scan the blockchain and know which pools are holding millions (or billions). The payout for finding a hole is right out in the open.
Researchers keep pointing out that while defenders spend tons of energy and money trying to plug every leak, attackers just need to find one way through.
DeFi limped along for years despite this lopsided risk because pulling off an attack demanded rare skills. You needed to know Solidity inside and out, understand blockchain quirks, hunt for obscure bugs, and pour in hours of work. Not many had that combination.
Artificial intelligence changed that practically overnight.
The latest research threw advanced AIs at piles of smart contracts, including ones that had been exploited in the real world before. The outcome? Pretty scary. The models found and repeated a big chunk of those attacks themselves — no hints required.
But here’s what’s really chilling: even when showing contracts created after the models’ last update, the AI still ferreted out vulnerabilities. It wasn’t just copying old scams; it was figuring out how to break new things, all by itself.
The AI did more than just spot weaknesses. It wrote up attack strategies, test-drove them, tweaked and improved until something worked. This is a step beyond older security tools that mostly just hammered away looking for simple bugs.
Now, spotting vulnerabilities isn’t just easier — it’s getting a whole lot cheaper. AI can comb through thousands of contracts at a fraction of the old cost, and the gap keeps growing as the tech improves. Researchers have watched as the “exploit value” created by AI shot up all through 2025.
It’s clear where this leads: attackers are getting tools that outpace what ordinary security teams can handle, and they’re doing it at scale.
This isn’t some future risk anymore. By April 2026, DeFi started seeing major attacks nearly every day — hundreds of millions vanished in just a few weeks.
Kelp DAO’s downfall is a good example. The exploit didn’t come from a bug in a lending protocol’s core code, but from shaky assumptions in the surrounding infrastructure. Once things went sideways, panic spread. Billions were yanked out of connected protocols by nervous users. Lesson learned: your code can be rock-solid, but if a weak link snaps somewhere nearby, you’re still in trouble.
Investors usually figure, hey, the big DeFi protocols have been poked and prodded for years — they must be the safest.
There’s some logic there. The top dogs have survived waves of attacks and market chaos.
But there’s a flip side. The bigger a protocol gets, the juicier the target. The payoff is huge, the incentive to hack goes up, and as these platforms sprawl out, so do their dependencies and weak spots. For AI scanning the landscape, the big names aren’t “trusted,” they’re “jackpot.”
Of course, not everyone’s on the panic train. Some in the industry argue that DeFi security keeps getting stronger. They’ll point to better audits, smarter risk tools, improved design, and fewer losses compared to how much value is in the system. Some researchers believe DeFi’s main lending protocols are way sturdier than just a few years ago.
There’s another factor, too — AI still spits out a ton of false positives. You need real people to sort out which flaws are dangerous. From that angle, maybe AI is arming both sides of the arms race, not just attackers.
Teams are already using AI to audit code and hunt bugs faster. But, naturally, attackers grab those same tools. There’s a race.
Others lean on formal verification — using math to show a smart contract does what it says it does. It’s solid, but only covers certain risks. Bug bounties work sometimes, paying ethical hackers to report holes — though criminals can often grab bigger rewards on their own.
Insurance is the last safety net, but the coverage out there is a drop in the bucket compared to the mountain of money in DeFi.
Here’s something most users miss: attacks aren’t just on the code anymore. Hackers are going after the stuff around your protocol — bridges, infrastructure, dev pipelines, repos, governance, you name it. A protocol can look secure on paper, but if the support beams get sawed out, you’re still in for a bad day. Traditional audits are no longer enough.
The biggest shocks have shown another truth: when things go south, it’s usually humans stepping in to stop the bleeding. Security councils, freezing contracts, admin overrides — these “emergency brakes” are getting more common.
It’s a sort of hybrid: DeFi code under human oversight. Fans say this keeps things safer. Purists argue it betrays the whole “code is law” promise the space was built on.
Here’s the crossroads: DeFi always promised, “just trust the code, not people.” But as AI-powered attacks ramp up, projects keep adding human oversight and controls. So, we’re back to trusting humans again — not exactly the original dream.
Maybe that’s safer. But it brings back the trust issues DeFi tried to wipe out.
No easy answer either way.
So what can anyone actually do? Pay attention to who controls the admin keys. Look at bridges and oracles, not just the core code. Remember, if protocols are linked, so are their risks. Don’t blindly trust insurance. Keep an eye out for creeping centralization. And above all, know that security is about a lot more than checking if someone audited the smart contracts.
At last, considering all
Manuel Arios’s warning forces the crypto world to face a hard truth.
AI hasn’t destroyed DeFi — but it’s definitely upset the old balance between attackers and defenders. No one knows for sure if DeFi gets safer or more vulnerable from here. What’s clear is that “audited code is safe” might not cut it anymore.
From now on, staying safe in DeFi will depend on how quickly we adapt — because the attackers aren’t going to wait, and machines don’t get tired.
The AI Exploit That Could Destroy DeFi⚠️ was originally published in Coinmonks on Medium, where people are continuing the conversation by highlighting and responding to this story.

