Polymarket's October 29, 2026 security breach marked Polymarket's second major vendor-related security breach in four months, following a June 25, 2026 attack that drained roughly $3 million

From the articlePolymarket Sends $3.9M Back to Traders After Vendor Script DrainAlso in Polymarket suffers second multimillion-dollar security breach in just four months, Polymarket Stops Trades Following Security Breach, Cites User Losses