Ethereum\u2019s Constantinople upgrade has gotten a delay following a critical security vulnerability identified by the smart contract audit firm ChainSecurity.\r\n\r\nAccording to a paper published by Chainsecurity, Constantinople enables new reentrancy attacks directed to "following, a short smart contract which is not vulnerable to a reentrancy attack before Constantinople, but vulnerable afterwards."\r\n\r\nLong story short, It is a serious bug that could cause funds to be stolen in some contracts.\r\n\r\n"The upcoming Constantinople upgrade for the Ethereum network introduces cheaper gas cost for certain SSTORE operations," the paper says. "As an unwanted side effect, this enables reentrancy attacks when using address.transfer(...) or address.send(...) in Solidity smart contracts. Previously these functions were considered reentrancy-safe, which they are not any longer."\r\n\r\nThe new fork date will be decided after the new Ethereum developers call on Friday.