What happened
On May 22, 2026, approximately $700,000 in POL was drained from Polymarket operational wallets on Polygon after a six-year-old internal private key was compromised. Public reporting said user deposits, open trades, and market settlement systems were unaffected.
How it happened
The attacker used the compromised key controlling an internal rewards and operations wallet, moved POL through a relay, and fanned the funds across multiple addresses and exchanges. This was an operational-wallet compromise, not a failure of Polymarket's core trading contracts.
Protocol details
Classification
Key Compromise
Protocol Type
DeFi Protocol
Implementation language
Solidity
Protocol links
Website
@Polymarket
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