For any crypto user watching a Web3 bridge protocol pause its transactions, a familiar fog of uncertainty descends. It is a moment of digital silence where the seamless flow of a multichain world grinds to a halt, replaced by the single, urgent question: are the funds safe?
This fog has enveloped the entire Web3 ecosystem, born from a critical vulnerability that is both indispensable and profoundly dangerous. Since 2021, an estimated $2.8 billion has been stolen from this infrastructure, representing roughly 40% of all value hacked from DeFi, according to a 2025 ACM study and data from Chainlink.
For any community navigating a bridge incident, understanding this global story is essential.
In Brief:
A Web3 bridge, also called a cross-chain bridge, is a protocol that allows assets to move between blockchains. They make decentralized finance interoperable, but also expose the largest single attack surface in crypto.
To understand why these bridges have become such high-value targets, it helps to break down how they work and how attackers dismantle them.
The attack patterns are now tragically familiar: a grim playbook of digital heists preying on the centralized chokepoints of a decentralized world. Sometimes, the breach is brutally simple.
Take the $625 million Ronin Bridge exploit in 2022: not a failure of smart contract code, but of human security. Attackers used a straightforward phishing scheme to seize five of the nine private keys needed to authorize withdrawals, effectively walking out the front door with the treasury.
Other times, the heist is a display of technical cunning. In the $320 million Wormhole hack, an attacker exploited a subtle flaw in the bridge’s signature verification code, tricking the protocol into minting 120,000 “wrapped” ETH on a different chain without posting any collateral.
It was, in every sense, the digital equivalent of printing money.
Occasionally, the systems break under their own complexity. The $190 million Nomad loss began when a routine update introduced an error that let anyone approve their own transactions.
The first transaction was quickly copied by hundreds more, resulting in what analysts called a “chaotic, crowd-sourced looting” of the bridge in mere hours.
“Cross-chain infra has enabled DeFi to scale,” the team behind the interoperability project Portal reflected in a 2025 post on X. “But it’s also become one of the largest attack surfaces in crypto, costing users billions.”
Even as billions have already been lost, 2025 reveals that the bridge problem is far from solved, and, in some ways, more complicated than ever. Multi-hundred-million-dollar exploits persist, but the broader threat landscape is evolving.
Bridges still stand as the largest single attack surface in Web3, according to Hacken’s H1 2025 report. Yet the year’s largest individual incident wasn’t a bridge hack at all: Chainalysis flagged the $1.5 billion ByBit service exploit.
Even when hackers strike elsewhere, bridges often play a starring role in laundering stolen funds. Elliptic’s 2025 report shows that a third of crypto-crime investigations now traverse three or more blockchains, with bridges acting as the getaway car for illicit assets moving across jurisdictions.
Experts call this the “interoperability trilemma”: the constant tradeoff between security, speed, and decentralization. Pick two, and the third suffers.
A 2025 ACM study of 15 bridges found that 70% still carried unpatched vulnerabilities—a stark reminder that the challenge remains urgent and unresolved.
The industry is responding with a spectrum of solutions designed to navigate this fog of risk. The path forward is being built on two parallel tracks: technological innovation and a new standard of operational security.
On the technology front, next-generation protocols are attempting to engineer the problem away.
At the same time, operational security is evolving into a non-negotiable standard. Mandatory third-party audits, robust public bug bounty programs, and a commitment to radical transparency during crises are increasingly the baseline for earning user trust.
Bridges have long been portrayed as the arteries of Web3. In practice, they often prove to be its most fragile links.
As the ecosystem experiments with these new models, one reality endures: users are still crossing a foggy landscape, where the ground beneath remains uncertain and a relentless focus on security is the only compass for those daring to traverse it.
