Ethereum's Glamsterdam upgrade was set to reach the Hoodi test network on Monday, Oct. 26 at 17:42:48 UTC. That won’t happen now, and no new date has been set.
Developers pulled the activation during Thursday’s All Core Devs Execution meeting. Security researchers found that a proposed change to Ethereum’s gas accounting could alter how existing smart contracts handle failed transactions, which could make some errors permanent.
One gas change at the center of the delay
The problem is EIP-8037. It changes how Ethereum charges for creating new records in its database, with the goal of limiting that database’s growth as the network raises the number of transactions it can process.
On Oct. 13, security firm ChainSecurity published an analysis showing that EIP-8037, combined with EIP-8038, could change how contracts react when another contract they call runs out of gas. Gas is the fee paid to the network’s operators.
Developers now want to look at how that change interacts with contracts that are already running on mainnet. Those contracts were written for the old rules.
How a failure could stick
Some contracts are built to catch a failed operation and keep going. They might log that an attempt failed, block further attempts or move to another step.
Developers sometimes count on the leftover gas being too low for those follow-up actions to finish. When the gas runs out, the whole transaction reverses, and nothing gets recorded.
Glamsterdam changes that math. Under the proposed rules, gas spent creating certain records can be returned when those changes are undone. That refund can leave enough gas for a contract to complete a failure-handling step that would have reversed before. A failure that used to wash out could get written down.
The risk also runs the other way
ChainSecurity calculated that creating a new storage slot could cost 110,020 gas once a separate allowance is used up. Under the old rules, the same operation costs 22,100 gas.
So a contract working from a fixed gas budget could fail partway through an operation that is otherwise valid.
There’s a limit to what’s been shown. ChainSecurity demonstrated the mechanisms. It hasn’t publicly shown that a major production protocol can be exploited. Its findings describe how existing software would behave under proposed rules, and they don’t indicate that any contract is being exploited through these changes today.
Where this leaves the rollout
Glamsterdam includes several changes beyond the gas rules, among them a new system for choosing block builders and improvements meant to let the network handle larger blocks.
The upgrade activated on the Sepolia testnet on Oct. 6. Hoodi was the next public rehearsal, and it was supposed to come with an increase in Hoodi’s gas limit to 200 million. That increase is on hold too.
Ethereum mainnet doesn’t have a confirmed Glamsterdam activation date. If you maintain a contract that depends on running out of gas to force a revert, read ChainSecurity’s Oct. 13 analysis before Hoodi gets a new date.
