An attacker harvested 74 replayable signatures from failed GalaChain bridge transactions over 55 days and drained ~2.0B GALA plus ~37 other tokens (~$3M) from nine wallets. Gala paused the bridge, revoked roles, and deployed a permanent fix.
On August 18, 2026, an attacker drained approximately $3 million (~2.0B GALA plus ~37 other tokens) from nine GalaChain wallets by exploiting a signature-scope confusion flaw in the bridge. The attacker harvested 74 replayable signatures from failed transactions over 55 days (the oldest 432,190 blocks prior). EIP-712 verification accepted caller-supplied type definitions, so a signature covering one field set authorized a different operation, and failed transactions rolled back their unique replay keys, leaving the signatures reusable. The first unauthorized transfer occurred at 02:21:54 UTC (block 10404040, 1,639,810,337.11548495 GALA in one call), with 1,066 submissions at a median 4.5-second interval, 73.9% one block apart, and 56 of 59 account-token pairs drained to exact balance on the first attempt. Gala paused the bridge at 05:09:19 UTC, revoked roles, and deployed a permanent fix at 06:27 UTC. No private keys or seed phrases were compromised. Gala filed an FBI IC3 complaint and sent freeze requests; CertiK (late 2025) and Hashlock (Jan 2026) reviews had missed the signature-scope issue.
The stolen proceeds were bridged out of GalaChain and traced across four chains. Gala filed an FBI IC3 complaint and sent freeze requests to exchanges and bridge operators.