Ethereum Developers Cancel Oct. 26 Glamsterdam Upgrade on Hoodi

Ethereum developers cancelled the Glamsterdam upgrade scheduled for Monday, Oct. 26, on the Hoodi testnet, leaving node operators needing software that will not activate the fork.

Ethereum Foundation DevOps contributor Barnabas Busa merged a rollback of Hoodi's network configuration on Oct. 22. It removes the execution- and consensus-layer activation settings, along with the scheduled increase in Hoodi's gas limit to 200 million.

“Revert to an older release without the Hoodi upgrade scheduled, or wait for your EL client team to release a new version that cancels the upgrade,” Protocol Watch Research & Advisory founder Christine D. Kim told operators in an Oct. 22 alert. EL refers to execution-layer software.

The cancellation requires changes to software already distributed. An open Besu pull request says Hoodi nodes running version 26.10.0 will still activate Amsterdam, Glamsterdam's execution-layer component, at the original timestamp until they run a release containing the reversal. Its changelog entry lists the cancellation under “Unreleased.”

Gas-Accounting Security Concerns

Kim attributed the cancellation to security issues identified by ChainSecurity. Those findings were also on the Oct. 22 All Core Devs Execution agenda.

ChainSecurity's analysis focuses on EIP-8037 and EIP-8038, which change state-creation and state-access gas accounting. It says the changes can replenish available gas or alter what the remaining gas can pay for, allowing a contract's failure-handling code to finish where it previously would have reverted. That can turn an operation that should remain retryable into a permanent failure, even without changes to the contract's code.

Glamsterdam's scaling changes previously covered by The Defiant include bringing proposer-builder separation into Ethereum's protocol and introducing block-level access lists to support parallel validation. The Ethereum Foundation's original Hoodi announcement said the upgrade activated on Sepolia on Oct. 6.

The rollback sets no replacement Hoodi date, and mainnet activation was already undecided. Before the cancellation, the Oct. 22 developer agenda said teams aimed to select a mainnet date at the following week's consensus call if Hoodi went smoothly.