An attacker exploited an arithmetic flaw in Tessellation’s metagraph fee-transaction accounting. A specially constructed batch of fee transactions caused an intermediate subtraction to underflow and wrap into a large positive balance, creating SWAP that was not backed by deposits. Because validation focused on the resulting batch state rather than validating each balance-changing operation individually, the final balances remained apparently valid and reconciled. The attacker created the unbacked SWAP in one snapshot and subsequently sold it into PacaSwap’s SWAP/DAG liquidity pool, extracting approximately 12.1M real DAG contributed by LPs. The flaw was specific to Tessellation’s metagraph fee-transaction path; Constellation’s Hypergraph and DAG supply were unaffected