Polymarket users lose about $2.7 million in third-party breach
On 29 October, malicious JavaScript distributed through a breach of an external service provider stole users' cryptoassets on Polymarket. The malicious code, linked to a website performance monitoring tool, hijacked login sessions to siphon funds, with about $2.7 million confirmed stolen directly from 726 wallets. Polymarket temporarily suspended trading before resuming it and said it would pay about $3.9 million in total compensation for direct losses and the trading suspension.
Key facts
- Affected organisation
- Polymarket
- Incident type
- Hacking & intrusion
- Occurred / detected
- 2026-10-29
- Scale of damage
- About $2.7 million in cryptoassets stolen from 726 wallets
- Cause / method
- Distribution of malicious JavaScript and hijacking of login sessions through the takeover of DNS records belonging to external monitoring service provider DebugBear
- Location
- Other countries
If your data was exposed
Exposed dataCrypto assets
- Check login and withdrawal history in your exchange app, and turn on withdrawal address whitelisting and withdrawal delays.
Timeline
- A breach of an external provider led to the theft of user funds and service disruptions on the Polymarket website.
- Polymarket resumed temporarily suspended trading and announced plans to compensate affected users.
- Plans were disclosed for Polymarket to pay affected users a total of $3.9 million in compensation.
- DebugBear disclosed that its DNS records had been taken over through its domain registrar, and the impact was confirmed as 726 wallets and about $2.7 million stolen directly.
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Other incidents at Polymarket
Polymarket hack estimated to have drained about $3 million in crypto assets
Impact: Estimated theft of about $3 million in crypto assets
Crypto assets were stolen from Polymarket in a hack, and an on-chain analyst estimated the losses at about $3 million. Polymarket said it had blocked and removed a malicious bug after a third-party supplier was hacked, and decided to fully reimburse affected users.
Related reports: 2 · last report →Polymarket hacked twice in three months
Polymarket was hacked twice in three months. A third-party login issue remains unresolved, and the dates and scale of the damage of each incident have not been confirmed.
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The summary and key facts are written by AI from related reports and may contain errors. Check the original articles and the organisation’s official statements for accurate details.