Polymarket Pauses Trading Following Front-End Security Exploit

What Happened to Polymarket?

Popular decentralized prediction market Polymarket hit a major operational roadblock on October 29, 2026, after users reported that their funds were being withdrawn without permission. In response to the sudden security threat, Polymarket immediately placed its exchange into cancel-only mode and paused relayer operations to protect traders.

By switching the exchange to cancel-only mode, traders are allowed to cancel their existing orders on the platform, but no new orders can be created or placed. Halting the relayer services also prevents automated tools from submitting signed transactions to the underlying blockchain.

Traders Sound the Alarm on Social Media

The security incident came to light after affected traders took to social media platform X to warn others about unauthorized drains from their wallets.

If you are a Polymarket user, lock down your account. I just got drained $800,000. Other accounts are also affected. Friend got drained $600k. Please be careful dont interact with the site.

The statement from trader Car On Polymarket highlighted the severity of the exploit, with individual user losses quickly escalating into hundreds of thousands of dollars.

Polymarket Statement and Official Response

Polymarket soon confirmed the exploit on its status page and official social channels, identifying the source of the flaw as a compromised third-party service provider.

The company stated that it has already escalated the incident to relevant law enforcement agencies. Out of an abundance of caution, operations were halted while security teams secured the infrastructure.

Polymarket reassured affected community members by promising that anyone who lost funds due to this incident will be made whole.

Tracking the Suspected Attacker's Wallet

On-chain data from analytics firm Arkham Intelligence identified the suspected attacker's wallet address as 0x3F99139F1C5854bb628c2e576Aaf638e99dFfc18.

Data shows that the address quickly amassed approximately $2.65 million in POL, which is the native utility token of the PolygonPOL+0.42% network. The attacker achieved this by executing multiple swaps from bridged USDCUSDC-0.09%.e) into POL using Relay, a cross-chain swapping protocol.

The initial string of suspicious transactions began shortly before the outage was declared, before transaction activity on the suspect wallet went quiet.

Technical Insights from Cybersecurity Researchers

Cybersecurity researchers at Hudson Rock provided key technical findings explaining how the malicious code was executed on the website.

According to Hudson Rock, a script hosted through Debug Bear—a service typically used for web performance monitoring—contained malicious wallet-draining code.

The rogue script was designed to search for active trading sessions of logged-in users. Once detected, the script attempted to automatically liquidate user positions and transfer the resulting funds away.

Hudson Rock revealed that the suspected attacker's wallet address was directly hard-coded as the fallback recipient within the script. Production site code records show that Polymarket has since removed the compromised script.

Researchers noted that it remains unclear how the initial compromise of the third-party provider occurred or exactly how many total users were impacted.

Past Security Exploits on Polymarket

This security event follows previous security challenges experienced by Polymarket earlier in the year.

In May, a private key compromise affected an internal top-up wallet, resulting in a loss of roughly $700,000.

A month later in June, another compromised third-party vendor enabled attackers to inject malicious code into the front-end interface. That breach drained approximately $3 million from fewer than 15 user accounts, after which Polymarket fully refunded all impacted victims.

Broader Crypto Market Background

Amid security headlines across decentralized applications, major cryptocurrencies like BitcoinBTC+0.28% continued to trade within normal daily ranges. Bitcoin was priced at around $80,847, down roughly 0.79% over 24 hours, with a high of $81,840, a low of $79,636, and daily trading volume hovering near $1.2 billion.

Past performance of digital assets or market providers is not a guarantee of future performance or returns. Traders are encouraged to exercise caution and utilize strong security practices when connecting wallets to online platforms. You can check market updates on Bitkub Market.