The Sandbox has paused SAND bridging on Base and BNB Smart Chain after disclosing a vulnerability in its cross-chain bridge. The project said the issue has been contained, but warned users not to buy, sell or trade SAND on the two affected networks while liquidity remains compromised.

According to The Sandbox, an attacker was able to mint unbacked SAND on Base and BNB Smart Chain. The project said SAND on Ethereum and Polygon was not affected, user wallets were not compromised, and the Ethereum-locked SAND that backs bridged balances remains intact.

The immediate action was to disable bridging to and from Base and BNB Smart Chain, isolating tokens on those networks so they cannot be moved or redeemed through the official bridge. The team said the impact represents less than 0.01% of the total SAND token supply, and it is preparing a pre-incident snapshot and compensation plan for qualified impacted liquidity providers.

Security firm Blockaid said it detected an exploit on the SAND OFT deployment on Base, describing the issue as a takeover of LayerZero delegate permissions via approveAndCall that allowed unbacked minting. Other reports said the large headline amount of minted tokens reflected face value rather than realized proceeds.

The conservative read is that this is a bridge and liquidity incident, not a compromise of the underlying Ethereum SAND token. The remaining open questions are the full technical cause, the final loss estimate, and when Base and BNB Smart Chain bridging can safely resume.