UNCX Vesting V2 exploit: share accounting root cause

≈$807,609 realized/routed economic value (UNCX incident report; UNCX calls it intentionally approximate). Returns: 82,143,476.362922687 X, 8.10335 ETH and 15.764812886973556558 ETH. Secondary figures disagree: Olympix ~$808K; Blockchain Breaches ~$1.49M.

Root cause: Per UNCX: release removed a position's active shares from global supply but kept its historical deposited-share record; after a direct token top-up inflated the token-per-share ratio, cancel reused the stale record and removed too many shares, so a small retained position redeemed a disproportionate share of the pool. No admin functions used.

Timeline, as sourced: 14 Oct 2026 (incident window); UNCX report published 15 Oct 2026, rescan cutoff 15 Oct 2026 16:40:35 UTC.

On 14 October 2026, attackers drained UNCX Smart Token Vesting V2 contracts on Ethereum, BNB Chain, Base and Robinhood Chain. According to the UNCX incident report (opens in a new tab), the vesting manager pools each token and tracks positions with internal shares. Releasing an immediately vested position removed its active shares from global supply but left its historical deposited-share record attached. Tokens sent directly to the manager raised the token-per-share ratio without minting shares. Cancelling then reused the stale record and removed too many shares, so a small retained position redeemed a disproportionate amount of the pool. UNCX counts 11 confirmed drain transactions across 10 tokens and puts realized or routed value at roughly $807,609. It states that the reviewed exploit calls did not use admin functions.