Kipseli PropAMM Router exploited for $72.35K via decimal/pricing mismatch between USDC and cbBTC on an unsupported swap path.
Security & Exploits ·
An MEV bot exploited a decimal and pricing mismatch in Kipseli PropAMM Router to extract approximately $72.35K in cbBTC by swapping 0.04 WETH (worth ~$95). The attacker used a WETH-to-cbBTC trading pair that the system did not officially support.
Kipseli's pricing is intended to be USDC-denominated, using 6 decimals, but the router processed the unsupported swap path and produced a quote at that scale. The integer value—92,610,395—was then transferred directly as cbBTC, which uses 8 decimals, resulting in 0.92610395 cbBTC worth roughly $72.35K instead of the ~$92.61 that a correctly scaled USDC transfer would have represented. The on-chain wrapper's signature mechanism binds only token identities and timestamp, not amounts or rates, leaving no validation layer to catch the directional mispricing.
The exploit occurred on April 22, 2026, affecting an inventory wallet. It remains unclear whether Kipseli has updated the signing logic to include amount validation or restricted unsupported trading pairs to prevent recurrence.