South Korean crypto exchange Upbit canceled HEMI trading support 18 minutes before its scheduled Sept. 9 launch after confirming that a smart-contract vulnerability affecting Hemi's early-contributor reward distribution had been exploited. The exchange had announced HEMI markets against Bitcoin and Tether on Sept. 8, but withdrew the listing after receiving and verifying a security-incident report during its continuing pre-launch monitoring. Hemi said approximately 124.5 million unclaimed HEMI tokens were removed in a Sept. 7 exploit of its legacy Genesis Drop contract, in which an attacker used a reentrancy vulnerability in a modified MerkleBox contract and later sold most of the tokens. Bithumb, which had already listed HEMI, designated it an investment caution item at 11:50 a.m. on Sept. 9 after identifying abnormal token withdrawals and unauthorized asset liquidation. Bithumb said it would announce in the second week of the following month whether to end trading support. Hemi said its core HEMI and veHEMI tokens, Hemi Virtual Machine, native tunnels and third-party bridges were unaffected.