Polymarket has temporarily stopped trading on its international platform after a security breach at one of its third-party service providers resulted in unauthorized withdrawals from user accounts.
The prediction market operator confirmed the incident on Thursday after several users took to X (formerly Twitter) to report that funds had disappeared from their accounts without permission.
CoinDesk also verified reports that users holding assets on Polymarket’s international venue had suffered losses following the breach.
In a notice published on its status page, the company said it had discovered and resolved the issue affecting the international platform. Polymarket attributed the incident to a compromised external provider and confirmed that the matter had been reported to relevant law enforcement agencies.
The platform also assured affected customers that they would be reimbursed. However, trading was suspended as the company responded to the security incident.
The latest breach marks the second time in recent months that Polymarket users have lost funds through a third-party security failure.
In June, another vendor experienced a security breach that affected Polymarket’s front-end infrastructure. That incident resulted in approximately $3 million in user funds being stolen.
According to figures tracked by DeFiLlama, the latest attack has caused estimated losses of roughly $2.7 million, slightly below the amount lost in June.
The report was updated on October 29, 2026, at 19:33 UTC with further information and again at 19:39 UTC to reflect the revised loss estimate.
