Across Protocol relayer loses under $4M in Solana attack
Across Protocols Risk Labs-operated relayer lost less than $4 million after an attacker fabricated $41.7 million in Solana deposit events, according to a post-incident report released by the cross-chain protocol. Across attacker forged 1,627 Solana deposits The attack occurred between 05:07 and 06:14 UTC on July 17, according to the Across Protocol post-mortem. The attacker used 1,627 single-use Solana wallets to create the same number of fake deposit events. Those deposits carried a combined face value of approximately $41.7 million and requested payments across 18 destination chains. Across reported that the funds were directed toward one recipient address on an Ethereum Virtual Machine-compatible network. Risk Labs relayer filled 581 requests before Across stopped Solana operations. Those payments represented about 35.7% of the fraudulent requests but only 10.8% of their stated value. The relayer advanced approximately $4.5 million of its own capital. Across invalidated the remaining 1,046 requests, preventing about $37 million in additional payouts. Approximately $500,000 belonging to the attacker remained trapped within the protocol. Across deducted that amount from the gross payout to place its net loss below $4 million. Why Across users avoided the relayer loss Across attributed the breach to a flaw in Risk Labs off-chain event-reading software rather than a vulnerability in its smart









