Ethereum developers have postponed the Glamsterdam network upgrade on the Hoodi testnet, previously scheduled for October 26, 2026, following concerns that proposed changes to gas accounting could affect existing smart contracts.
The Ethereum Foundation confirmed the decision on October 22, stating that developers require additional time to investigate interactions between Ethereum Improvement Proposal 8037 (EIP-8037) and contracts already deployed on mainnet.
The postponed activation was scheduled for epoch 132,352, slot 4,235,264, at 17:42:48 UTC. It would have introduced Glamsterdam’s execution and consensus changes while increasing Hoodi’s gas limit to 200 million.
Both the upgrade and accompanying gas-limit increase have now been removed from the testnet’s scheduled configuration.
The decision follows security research identifying potential compatibility problems in deployed applications. No replacement Hoodi activation date has been announced, and Ethereum’s mainnet upgrade remains unscheduled.
EIP-8037 Raises Concerns Over Existing Smart Contracts
Glamsterdam introduces several changes intended to increase Ethereum‘s processing capacity and improve transaction execution. Among them, EIP-8037 increases and separately meters the gas costs associated with creating blockchain state, while EIP-8038 adjusts state-access pricing.
These changes are intended to align transaction fees more closely with computational and storage requirements. However, blockchain security firm ChainSecurity identified potential unintended consequences involving smart contracts that rely on existing gas-consumption behavior.
Under certain conditions, the proposed accounting changes could alter how applications handle failed internal operations. Contracts that previously reverted an entire transaction after an operation exhausted its gas allowance might instead continue executing subsequent instructions.
That difference could affect applications using automated retry mechanisms, withdrawal processing or batched transactions. ChainSecurity reported identifying 13 real-world examples of affected contracts and said it was coordinating responsible disclosure with relevant developers.
The findings do not establish that the vulnerabilities have been exploited on Ethereum mainnet. Rather, they identify potential problems that could emerge if the proposed rules were activated without additional safeguards. Ethereum developers discussed the concerns during the October 22 All Core Developers Execution meeting, designated ACDE #248, before agreeing to postpone Hoodi activation.
Hoodi Delay Creates Uncertainty for Mainnet Schedule
The postponement interrupts Ethereum’s planned sequence of testnet deployments ahead of Glamsterdam’s eventual mainnet rollout.
The upgrade successfully activated on Sepolia on October 6, providing an earlier testing environment for its execution and consensus changes. Hoodi was scheduled to become the next major testing milestone, including a substantial increase in the network’s gas limit.
Glamsterdam’s principal features include enshrined proposer-builder separation, introduced through EIP-7732, and block-level access lists under EIP-7928. Together, these mechanisms aim to improve block production, parallel processing and transaction validation efficiency.
The Ethereum Foundation clarified that postponing the upgrade changes future activation settings without reversing Hoodi’s existing blockchain history. Node operators and validators must now ensure their execution and consensus clients reflect the revised configuration.
The Foundation specifically warned operators not to assume that previously published client releases automatically incorporate the postponement. Updated releases and instructions will be provided by individual client teams.
The development also complicates planning for a potential December mainnet activation. Developers had considered December 1, 8 and 9 as possible deployment dates, but none had been formally adopted. Further testing and potential modifications to EIP-8037 could affect that timetable.
For Ethereum users and ETH holders, the postponement requires no immediate action because it concerns a testnet rather than the live network. For application developers, however, the compatibility findings highlight the importance of testing contracts against revised gas rules before mainnet deployment.
The next milestone will be an updated Hoodi schedule following additional investigation of EIP-8037’s impact on deployed applications.