Ethereum delays Glamsterdam test after security devs flag risk to existing contracts
Ethereum developers have postponed the Glamsterdam upgrade on the Hoodi test network after security researchers identified a problem that could change how existing smart contracts handle failed transactions.
The upgrade was originally scheduled to activate on Oct. 26 at 17:42:48 UTC. Developers made the decision to postpone during Thursday's All Core Devs Execution meeting to investigate how proposed changes to Ethereum's gas accounting might interact with contracts already running on the main network.
Gas accounting concerns
The issue centers on EIP-8037, which changes how Ethereum charges for creating new records in its database. This proposal aims to limit database growth as Ethereum increases transaction throughput. When combined with EIP-8038, these changes could alter how contracts respond when another contract they call runs out of gas.
ChainSecurity found that EIP-8037 and EIP-8038 could leave some contracts with more or less gas than expected, potentially making errors permanent or causing otherwise valid operations to fail.
Contract behavior changes
Some contracts are designed to catch failed operations and continue processing, sometimes relying on remaining gas being too low for those actions to finish, causing the entire transaction to reverse. Glamsterdam changes this calculation by allowing gas used to create certain records to be restored when those changes are undone.
This restoration could leave enough gas for a contract to complete failure-handling operations that previously would have reversed. Conversely, ChainSecurity calculated that creating a new storage slot could require 110,020 gas when a separate allowance is exhausted, compared with 22,100 under the old rules, potentially causing contracts to fail during otherwise valid operations.
Upgrade status
Glamsterdam brings several changes to Ethereum, including a new system for choosing block builders and improvements intended to let the network handle larger blocks. It completed its Sepolia testnet activation on Oct. 6. Hoodi was the next public rehearsal, alongside a planned increase in its gas limit to 200 million — which has also been postponed.
No replacement date has been announced for the Hoodi test or its planned 200 million gas limit, and Ethereum's mainnet upgrade date remains unconfirmed. ChainSecurity has demonstrated the mechanisms but has not publicly established that a major production protocol is exploitable.
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