South Korean Exchanges Flag The Sandbox’s SAND Token Amid Bridge Exploit

South Korean crypto exchanges Upbit and Bithumb have designated The Sandbox’s SAND token as an investment‑caution asset following a cross‑chain bridge exploit that remained unresolved.

Reason for the caution

Both exchanges cited an “unexplained or unresolved security incident” involving the SAND smart contract on the Base and BNB Smart Chain networks. The incident allowed an attacker to mint unbacked SAND tokens, prompting The Sandbox to disable bridging to and from those chains.

Exchange actions

• Upbit placed SAND under its trading‑caution framework on Aug. 24, suspending deposits and withdrawals for KRW and BTC markets while keeping trading open.
• Bithumb halted deposits and withdrawals on Aug. 22 and issued its own caution notice on Aug. 24.
• Both exchanges will review the situation; Upbit’s review runs through late September, while Bithumb expects a decision in the first week of October.

Impact on the token

The Sandbox reported that the vulnerability affected less than 0.01 % of SAND’s total supply. Balances on Ethereum and Polygon were unaffected, and no user wallets were compromised. Bridging on Base and BNB Smart Chain remains disabled, and the project is preparing a compensation plan for affected liquidity providers.

Potential outcomes

Depending on the review findings, either exchange could remove the caution, extend the review period, or terminate trading support for SAND. Upbit has already removed SAND from new borrowing applications, though existing loans may continue until maturity.

Context of Korean exchange cautions

South Korean exchanges have previously placed tokens under caution after security breaches, such as Taiko in June and Flow in December 2025. These actions are part of broader regulatory scrutiny under the country’s Virtual Asset User Protection Act.