EtherVista pair drained via K-invariant overflow

'~18.6K', per SlowMist (unit as given).

Root cause: Per SlowMist: 'The EtherVistaPair.swap() function suffers from an integer overflow in its K-invariant check. Since both reserves are uint112, their multiplication overflows and wraps around.'

Timeline, as sourced: Exploit tx 9 Oct 2026 03:47:59 UTC (on-chain); SlowMist alert 05:20 UTC.

On 9 October 2026 an attacker drained WETH and VISTA from an EtherVista pool on Ethereum (transaction (opens in a new tab)). According to SlowMist (opens in a new tab), EtherVistaPair.swap() checks the constant-product invariant by multiplying two uint112 reserves; the product overflowed and wrapped, so the check passed even when the real reserve product fell sharply. SlowMist says the attacker ran two crafted swaps through an attacker-controlled contract registered as the authorized router, and puts the loss at about 18.6K. No statement from EtherVista was found.