Ethereum Delays Glamsterdam Upgrade on Hoodi Testnet

Ethereum core developers have postponed the Glamsterdam upgrade on the Hoodi testnet, canceling its October 26, 2026 activation while investigating potential compatibility issues involving existing Ethereum smart contracts. The upgrade had been scheduled for epoch 132,352, but developers have not announced a replacement date.

According to the Ethereum Foundation’s official announcement, the decision was reached during All Core Developers Execution (ACDE) call #248 on October 22. The postponement centers on EIP-8037, a proposal modifying Ethereum’s gas-accounting framework, whose interactions with contracts already deployed on mainnet require additional examination.

EIP-8037 Review Interrupts Hoodi Activation Plans

EIP-8037 introduces changes to how Ethereum accounts for certain state-related operations, making compatibility with existing contract execution an important consideration. Developers are examining whether the proposed accounting rules could produce unintended behavior in applications designed around current gas costs and execution assumptions. The Foundation has not characterized the investigation as an active mainnet vulnerability.

The postponement affects multiple components of Glamsterdam. Both the Amsterdam execution-layer upgrade and the Gloas consensus-layer activation have been removed from Hoodi’s schedule, alongside a planned increase in the testnet’s gas limit to 200 million. All three changes had been scheduled for the same activation epoch.

Importantly, removing the activation does not reverse previously processed transactions or alter Hoodi’s existing blockchain history. The adjustment concerns future network configuration, preventing clients from activating protocol changes at the previously assigned timestamp.

The decision follows earlier challenges encountered during Glamsterdam’s development and testing. Previous devnets experienced consensus-finality problems and execution-layer issues, while Sepolia’s October 6 activation marked the upgrade’s progression into public testnet testing. The latest postponement demonstrates that successful activation on one testnet does not eliminate compatibility concerns elsewhere.

Ethereum Node Operators Face Revised Client Requirements

Hoodi node operators must ensure their execution and consensus clients reflect the canceled activation before October 26. Software retaining the previous fork configuration could become incompatible with the revised network rules, making updated client releases operationally important despite the postponement.

The Foundation has confirmed compatible releases including Lodestar v1.50.1, Lighthouse v8.3.2, Nimbus v26.10.2, Prysm v7.3.1 and Teku 26.10.2 for consensus infrastructure. Execution-layer releases include Besu 26.10.1, Geth v1.17.10, Nethermind 2.2.1 and Reth v2.8.1, among others. Validator operators must also verify their validator-client configurations and any external block-building infrastructure.

These requirements reinforce the distinction between Ethereum client software releases and network-wide protocol activation. Installing compatible software does not mean Glamsterdam has activated, particularly when the associated fork schedule has been withdrawn.

For application developers, the canceled activation removes a previously established testing milestone. Testing environments and deployment plans dependent on Hoodi’s October 26 transition will need adjustment once developers establish a replacement schedule.

Ethereum mainnet remains unaffected by the postponement, and ETH holders are not required to take action. No definitive Glamsterdam mainnet activation date has been established, leaving the remaining rollout dependent on further compatibility assessments and coordinated client readiness.