Gravity Bridge, a cross-chain protocol built on Cosmos, was hit by a key compromise attack over the weekend, resulting in the theft of about $5.4 million. This latest security breach adds to the growing list of exploits in the decentralized finance (DeFi) space so far in 2026.
Gravity Bridge Hack Linked to Signing Key Compromise: Investigator
On Saturday, May 31st, blockchain investigator Specter pointed out that Gravity Bridge may have been exploited through what he called a signing key compromise. In simple terms, a signing key compromise happens when a cryptographic key is stolen or exposed without authorization. This allows an attacker to decrypt sensitive information, forge digital signatures, or gain unauthorized access to systems—and in this case, to funds.
Related Reading: AAVE Price Drops 26%: $9 Billion in Net Outflows Linked to Kelp DAO Hack
The analyst revealed that the stolen assets included about $5.4 million in crypto, such as $4.3 million in USDC, 274 wrapped Ether worth roughly $553,000, $434,000 in USDT, and 14.16 PAXG tokens valued at around $64,000. According to security firm PeckShield, the attacker has already laundered some of the stolen funds through the ChangeNOW and Binance exchanges, but still holds over 2,100 Ether (worth about $4.23 million).
The Gravity Bridge team confirmed the attack on Saturday and advised validators and orchestrators to stop their operations while they investigate the exploit. “Thanks to the quick response from validators, the bridge is currently paused as investigations continue,” the protocol said in a follow-up social media post.
Gravity Bridge is a cross-chain protocol that works by locking tokens on the Ethereum network and creating direct copies of those assets on the Cosmos network. It relies on validator signatures to approve each transfer. This means that if an attacker gets hold of the right signing keys, the protocol would treat even fake transactions as legitimate.
If confirmed as a key compromise, this Gravity Bridge incident fits a pattern seen in many crypto bridge attacks, where breaches usually involve access controls rather than flaws in the smart contract code itself. This pattern is clear in most recent exploits, with Kelp DAO’s $292 million attack being a notable example.
Crypto Hacks Continue to Mount in 2026
As mentioned earlier, Gravity Bridge’s $5.4 million hack adds to the growing list of attacks that have shaken the crypto industry, especially the DeFi sector, in 2026. Bridges, in particular, have been a common target for attackers during this period. For instance, a TRM Labs report identified April 2026 as the most hacked month in crypto history, with the highest number of incidents. These attacks included the $292 million Kelp DAO hack and Drift Protocol’s $285 million loss.
Related Reading: Can Ripple’s Fed Master Account Approval Spark a New XRP Bull Run? AI Model Suggests $80 Is Possible
Featured image from Shutterstock, chart from TradingView
Frequently Asked Questions
Here is a list of FAQs about the Gravity Bridge 54 million attack written in a natural clear tone
BeginnerLevel Questions
1 What exactly is Gravity Bridge
Gravity Bridge is a tool that lets you move digital assets between different blockchains specifically between the Ethereum network and the Cosmos ecosystem Think of it as a secure tunnel connecting two separate cities
2 What happened in this attack
An attacker found a bug in the Gravity Bridge code and exploited it to steal about 54 million worth of various crypto tokens that were being held by the bridge
3 Did the attacker steal money from regular users like me
No The attacker stole the tokens that were parked in the bridges smart contract If you had tokens sitting in the bridge waiting to be moved those were taken However if you were just using the bridge normally to transfer funds your personal wallet was not directly hacked
4 Is my money safe if I used Gravity Bridge in the past
If you moved your tokens across the bridge and then withdrew them to your own wallet before the attack your funds are safe The issue was only with funds that were still locked inside the bridges contract at the time of the exploit
5 Was the attack fixed
Yes The Gravity Bridge team paused the bridge immediately after discovering the attack They then deployed a fix to prevent the same bug from being used again The bridge is now back online and operating normally
AdvancedLevel Questions
6 How exactly did the attacker exploit the bridge
The attacker used a reentrancy attack This is a classic smart contract bug Basically the bridges code allowed the attacker to call a function that would send them tokens but before the bridge finished updating its own records the attackers contract called the same function againtricking the bridge into sending tokens multiple times
7 Which tokens were stolen
The attacker stole a mix of tokens primarily Wrapped Ether and USD Coin The total value was roughly 54 million at the time of the attack
8 Did the Gravity Bridge team try to recover the funds
Yes The team quickly contacted the attacker through an onchain message offering a 500000 white hat