Ethereum and Solana accounted for the largest share of cryptocurrency hack losses during the first half of 2026, according to new research from blockchain security firm Blockaid, with private key compromises emerging as the dominant attack vector across both networks.
Ethereum Remains the Prime Target
Blockaid's latest report found that Ethereum continued to bear the heaviest losses among all blockchains in the first six months of 2026. As the most established smart contract platform and home to the deepest pools of liquidity in decentralized finance, Ethereum consistently attracts the greatest volume of attacker activity.
The concentration of value locked in Ethereum-based protocols makes it a persistent focus for bad actors seeking large payouts. That dynamic has held steady across multiple reporting periods, cementing the network's position at the top of the losses ranking once again.
When the money is deepest, so is the danger — Ethereum's dominance in DeFi keeps it squarely in attackers' crosshairs.
Solana Climbs the Rankings
The more notable shift in the data was Solana's rise to the number two spot, displacing Arbitrum as the network with the second-highest losses. According to Blockaid, much of the damage on Solana stemmed from key compromises rather than smart contract exploits.
Private key theft — in which attackers gain direct access to wallets or administrative controls — has proven to be a particularly costly weakness. These incidents often bypass code-level defenses entirely, targeting the human and operational layers of security instead.
Key takeaways from the report include:
- Ethereum held the top position for total hack losses in H1 2026.
- Solana overtook Arbitrum to rank second in losses.
- Key compromises drove a large portion of the damage across affected chains.
The findings underscore an ongoing challenge for the industry: even as protocols harden their code, the theft of credentials and private keys remains one of the most effective and damaging methods available to attackers.