Stop overpaying - start transferring money with Ogvio. Sign up, invite friends & grab Rewards now! 🎁
Truebit Hack Lets Attacker Mint $26 Million in Tokens for Free
Last Updated: January 13, 2026
✓ Fact Checked
Key Takeaways
- A code flaw in Truebit’s smart contract let an attacker mint $26 million in tokens almost for free;
- The issue came from missing overflow protection in an arithmetic operation within the Purchase contract;
- Solidity version 0.6.10 lacked automatic overflow checks, causing calculations to reset near zero.
A vulnerability in Truebit’s code enabled an attack that generated about $26 million in new tokens.
The flaw allowed the attacker to create tokens almost for free, which shows that even long-running blockchain systems can still be at risk.
According to a report from the blockchain security firm SlowMist, the issue was linked to how Truebit’s smart contract handled payments. The attacker exploited a contract error that allowed them to generate large amounts of tokens “without paying any ETH
Did you know?
Want to get smarter & wealthier with crypto?
Subscribe - We publish new crypto explainer videos every week!
The Most Rewarding Play-to-Earn Project? BitDegree Explained (ANIMATED)
SlowMist explained that a small arithmetic error caused the problem. The report stated, "Due to a lack of overflow protection in an integer addition operation, the Purchase contract of Truebit Protocol produced an incorrect result when calculating the amount of ETH required to mint TRU tokens".
That error enabled the attacker to mint $26 million worth of TRU tokens with almost no cost. The post-mortem noted that the smart contract’s code “erroneously reduced” the price calculation.
The issue was linked to the version of Solidity used to write the contract, version 0.6.10. Earlier versions of the programming language lacked automatic checks to prevent numerical overflow.
When a number went beyond the maximum value for “uint256", it would loop back to a small number near zero.
Trust Wallet’s browser extension v2.68 suffered a $7 million breach. How did the incident happen? Read the full story.
Loading...
The Most Liked Crypto News Findings
Looking for more latest crypto news on related topic? We have gathered similar news articles for you to spare your time. Take a look!
Latest Crypto News & Videos
![How to Transfer Money Without Fees? [Animated Tips 2025]](https://assets.bitdegree.org/youtube/crypto-finally-explained/how-to-transfer-money-without-fees-animated-tips-2025.jpg?tr=w-400 "How to Transfer Money Without Fees? [Animated Tips 2025]")
