Ethereum has postponed the next testnet phase of Glamsterdam on Hoodi after ChainSecurity discovered that new gas rules could push existing smart contracts into execution branches developers did not intend. On November 6, the Ethereum Foundation published eight technical assumptions that EIP-8037 and EIP-8038 could break, and asked projects and audit firms to review both contracts and off-chain systems before resuming the hard fork process.
Glamsterdam is an important step in Ethereum Layer 1’s throughput expansion plan, so the ongoing review not only impacts the testing schedule but also introduces additional uncertainty to the overall rollout roadmap. As the scope of affected contracts remains undetermined and some contracts are difficult to upgrade, developers have not set a new activation date on Hoodi or a timeframe for deploying Glamsterdam to the mainnet.
Glamsterdam’s Hoodi Rollout Remains on Hold
Glamsterdam was originally scheduled for activation on Hoodi at 17:42:48 UTC on October 26, 2026, at epoch 132,352 and slot 4,235,264. Core developers postponed the plan during All Core Developers Execution meeting #248 on October 22, after ChainSecurity warned that gas changes could create compatibility risks with deployed smart contracts.
According to the Ethereum Foundation’s announcement, this decision removed the activation schedule for Amsterdam at the execution layer and Gloas at the consensus layer from Hoodi’s configuration. The schedule to raise the testnet gas limit to 200 million at the same epoch was also removed. The changes only apply to the configuration of a fork that has not yet occurred, without reversing any part of Hoodi’s blockchain history.
Glamsterdam was previously activated on Sepolia on October 6. Hoodi was chosen as the next public testnet to test the upgrade before Ethereum advances to the mainnet preparation phase. However, ChainSecurity’s discovery caused the deployment process to halt between the two testing milestones.
How the Gas Changes Could Alter Contract Behavior
ChainSecurity identified the issue in the interaction between EIP-8037’s state-gas reservoir and the new state access fee structure in EIP-8038. In some cases, gas spent on state creation could be restored after an intermediary call reverts or the newly created state is deleted. The remaining gas along these call paths could increase during execution.
Contracts that continue processing after an external call fails are directly affected by these changes. A failure handler that previously lacked sufficient gas to write state and was forced to revert the entire transaction may now continue running. The contract could then save a failed state even though the external action was not completed.
In an analysis published on October 13, ChainSecurity described a failed ETH transfer operation via an intermediary contract. The gas returned after the revert command still allowed the original contract to update its internal balance, reducing the user’s withdrawal allowance even though they had not received the ETH. The company stated that the example was simplified, while real-world cases are being handled through a responsible disclosure process.
Cost increases could also render fixed gas budgets obsolete. Figures published by Ethereum show that the total cost of writing from zero to non-zero into a cold storage slot increases from 22,100 to 110,020 gas. Creating a new account requires 183,600 state gas plus execution cost. Contracts, bots, and relayers that use fixed gas limits may need adjustments before Glamsterdam is deployed.
Eight Assumptions Now Under Review
The Ethereum Foundation expanded the review by requesting developers and auditors to check projects against eight gas assumptions that may no longer hold true after Glamsterdam. They mainly concern how contracts handle out-of-gas and reverted calls, the accuracy of fixed gas budgets, and the capability of off-chain systems to confirm transaction status.
Most findings currently focus on contracts using fixed gas budgets, gas reserves, or stipends. The scope of inspection also covers wallets, bots, relayers, and simulation tools with hard-coded gas limits. These components may supply insufficient gas or misevaluate transaction results once the new mechanism takes effect.
At ACDE #248, ChainSecurity stated that it had identified 13 projects showing signs of being affected, including several major DeFi applications. The identities of the projects have not been disclosed due to the responsible disclosure process. The company also noted that the search did not fully cover front ends, off-chain tools, or Layer 2 deployments, so the total number of affected projects remains undetermined.
What Ethereum Developers Need to Resolve Next
The Ethereum Foundation stated that review results from ChainSecurity, Dedaub, and affected projects will be brought into upcoming All Core Developers meetings. Findings regarding specific contracts are being received through private channels while responsible disclosure continues.
Core developers have not yet decided whether to keep or adjust EIP-8037 and EIP-8038. Review results will be used to determine a new activation schedule on Hoodi, while mainnet plans remain open.
