Polymarket loses $700,000 to private key compromise

1 · Molly White · June 16, 2026, 12:39 a.m.
Summary
A recent security breach at Polymarket resulted in the theft of around $700,000 after a private key was compromised. The incident was identified by crypto researcher zachxbt, who noted that the compromised admin address had drained $520,000 at the time of reporting. Following the breach, Polymarket confirmed the vulnerability was due to an outdated private key, which will be replaced with a managed key in the future.