Ethereum Postpones Glamsterdam Hoodi Testnet Launch Over Gas Security Concerns

Ethereum developers have put off the Glamsterdam hard fork on the Hoodi testnet after researchers flagged gas related risks that could change how existing smart contracts deal with failed transactions. The Ethereum Foundation said the upgrade, planned for Oct. 26, will wait while developers study how certain proposals interact with contracts already live on the network. The pause clouds the mainnet schedule, since developers had been eyeing early December and planned to lock in a date after a clean Hoodi run. Glamsterdam had already gone live on the Sepolia testnet on Oct. 6.

How Glamsterdam Gas Changes Could Weaken Smart Contract Safeguards

On Oct. 13, blockchain security firm ChainSecurity warned that two proposals in the upgrade, EIP-8037 and EIP-8038, could weaken defenses against insufficient gas griefing. In that attack, a malicious caller supplies too little gas for a legitimate operation to succeed. Under the new rules, gas could flow back to a contract after a failed step, letting it keep running when it once would have halted, which could break checks that depend on remaining gas. A contract might then permanently log a failure, such as erasing a user’s claim or disabling a retry, leaving a valid action impossible to finish.

Real-World Contract Risks and Developer Reaction

ChainSecurity said it found 13 real-world examples of potentially affected contracts and is working on responsible disclosure with the projects, without naming them. It urged developers to inspect their contracts quickly. Security researcher pcaversaccio called the risks serious on Oct. 21 and asked for the hard fork to be reassessed. The Ethereum Foundation had earlier cautioned that the new gas model could break wallets, indexers and gas estimators built on fixed assumptions.