Hack history / 2026 / Hack or exploit
Polymarket International
Hack or exploit on Oct 29, 2026 · Supply Chain Attack
SOURCES AGREE ON DATE AND LOSS · 2 SOURCES
Lost
$2.7M
dollars at the time
Returned
none listed
as the sources state it
Rank
#613
among thefts by dollars lost
What happened
Attackers reportedly compromised a third-party website monitoring service used by Polymarket, allowing malicious JavaScript to execute on its international trading platform. The script hijacked authenticated trading sessions to sell prediction-market positions and transfer assets to attacker-controlled wallets. Polymarket temporarily suspended trading, removed the affected integration, and committed to reimbursing impacted users
Details
- Date
- Oct 29, 2026
- Kind
- Hack or exploit
- Method
- Supply Chain Attack
- How in
- Keys, accounts and infrastructure
- Target
- Prediction Market
- Chains
- Polygon
After the theft
- Victims reimbursed
- yes, amount not stated
“Polymarket temporarily suspended trading, removed the affected integration, and committed to reimbursing impacted users” (DefiLlama)
Reported by
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Cite this page
SwanBluechip, "Polymarket International hack, Oct 29, 2026: $2.7M lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht1fa9f01d3c/ (data as of 2026-11-01).