Ethereum Developers Cancel Oct. 26 Glamsterdam Fork on Hoodi Testnet
Ethereum developers have cancelled the October 26 Glamsterdam activation on the Hoodi testnet. Node operators are told to avoid fork-enabled builds. The upgrade already ran on Sepolia, but the floated early December mainnet window now looks less certain.
Glamsterdam will not go live on the Hoodi testnet on October 26 as planned. Ethereum developers have called off that activation, and node operators are being told to run client software that does not include the scheduled fork. The mainnet activation date remains undecided.
The Hoodi fork had been set for October 26, 2026 at 17:42:48 UTC, corresponding to epoch 132,352. Under that plan, operators were to upgrade both execution and consensus clients to fork-ready versions before the activation epoch, with Lodestar 1.50.0 and Nimbus 26.10.1 listed as compatible releases. The revised guidance reverses that: Hoodi operators should avoid running a fork-enabled build for now.
The reports do not say why the activation was cancelled or who announced it, and they give no date for the decision itself.
What Glamsterdam contains
Glamsterdam is a combined upgrade. It pairs execution-layer changes, codenamed Amsterdam, with consensus-layer changes, codenamed Gloas. Its headline feature is enshrined proposer-builder separation (ePBS), implemented mainly through EIP-7732. The upgrade also includes block-level access lists and gas pricing adjustments.
On Hoodi, the block gas limit target was expected to rise from roughly 60 million to 200 million after the fork.
Who needs to act
ETH holders and mainnet node operators do not need to take any action. Hoodi node operators and validators do need to follow the revised guidance. Running the wrong build on a testnet costs no real funds, and the upgrade has already run on another network: Glamsterdam activated on the Sepolia testnet on October 6, 2026.
Mainnet timing in question
The practical cost is schedule risk. Early December had been floated as a candidate mainnet window. With the Hoodi activation cancelled, that window looks less certain, although no change to the mainnet timeline has been announced and no mainnet date had been set.
The cancellation also comes as the fork's mechanics face closer scrutiny. Lido Head of Engineering Dima Gusakov has warned that shared deposit queues around the fork could let a malicious node operator hijack staker ETH. He also noted that a consensus-specs fix was closed as "not planned," which leaves pre-deposit checks to staking protocols. Nothing in the reports on Hoodi ties that issue to the cancellation.
For now, the signal is narrow. One testnet stage has been pulled from the schedule, and another testnet has already run the fork. The next step toward mainnet has not been announced. Until developers issue new instructions, Hoodi operators should stay off fork-enabled builds.
