Built an open-source tool to detect a known Polymarket…
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Built an open-source tool to detect a known Polymarket exploit
Polymarket has a known exploit where attackers use incrementNonce() on the CTF Exchange to cancel losing orders after they've already been matched on the off-chain orderbook. This was publicly disclosed on Feb 19 and has cost traders thousands.
If you run bots on Polymarket's BTC 5-minute markets, you may have experienced 'ghost fills' — orders that match on the CLOB but never settle on-chain.
The exploit: bad actors call incrementNonce() on the CTF Exchange contract to invalidate their losing orders after matching. They keep only winning sides.
I built Nonce Guard — a free, open-source monitoring tool that:
- Watches Polygon blocks in real-time for incrementNonce() calls
- Builds exploiter address blacklists
- Emits universal alerts (file/socket/webhook) any bot can consume
- Includes counterparty checking
Repo: https://github.com/TheOneWhoBurns/polymarket-nonce-guard
MIT licensed. Works with any Polymarket bot.
#cryptocurrency
Polymarket has a known exploit where attackers use incrementNonce() on the CTF Exchange to cancel losing orders after they've already been matched on the off-chain orderbook. This was publicly disclosed on Feb 19 and has cost traders thousands.
If you run bots on Polymarket's BTC 5-minute markets, you may have experienced 'ghost fills' — orders that match on the CLOB but never settle on-chain.
The exploit: bad actors call incrementNonce() on the CTF Exchange contract to invalidate their losing orders after matching. They keep only winning sides.
I built Nonce Guard — a free, open-source monitoring tool that:
- Watches Polygon blocks in real-time for incrementNonce() calls
- Builds exploiter address blacklists
- Emits universal alerts (file/socket/webhook) any bot can consume
- Includes counterparty checking
Repo: https://github.com/TheOneWhoBurns/polymarket-nonce-guard
MIT licensed. Works with any Polymarket bot.
#cryptocurrency
| 2,000 mlx | |
| 5 | |
| 0 |