Ethereum postpones Glamsterdam after EIP-8037 raises security concerns

Ethereum developers have postponed the Glamsterdam upgrade on the Hoodi testnet over smart contract compatibility concerns, canceling its October 26 activation and a planned increase to a 200 million gas limit.

According to the Ethereum Foundation’s October 22 announcement, the decision followed discussions during the All Core Developers Execution meeting, where developers agreed to investigate how EIP-8037 interacts with existing mainnet contracts. The Foundation has not announced a replacement testnet activation date.

Ethereum postpones Glamsterdam on Hoodi testnet

The upgrade was originally scheduled to activate on October 26 at 17:42:48 UTC, corresponding to Hoodi epoch 132,352. Developers have removed the Amsterdam execution-layer activation and the Gloas consensus-layer activation from the revised configuration.

The postponement removes the scheduled increase in Hoodi’s gas limit to 200 million, which developers intended to examine alongside other protocol changes. However, the Foundation clarified that this adjustment affects a future network upgrade and does not reverse Hoodi’s existing transaction history.

The decision changes the previously announced Hoodi schedule, as crypto.news reported on October 19. The testnet activation was intended to examine how execution and consensus clients handled Glamsterdam’s changes before developers selected a mainnet date.

Ethereum researcher Christine D. Kim warned Hoodi node operators that the October 26 activation had been canceled. She advised operators to revert to suitable older software versions or install updated execution clients that remove the scheduled upgrade.

PSA: Hey #ethereum node operators who are on the #hoodi testnet, PLEASE NOTE THE HOODI UPGRADE NEXT MONDAY HAS BEEN CANCELLED. 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. TY!

— Christine D. Kim (@christine_dkim) October 22, 2026

ChainSecurity identifies risks in Ethereum gas changes

The postponement follows concerns involving EIP-8037, which introduces separate accounting for gas consumed when creating blockchain state. Another proposal, EIP-8038, changes the costs associated with accessing existing state.

In an October 13 technical assessment, blockchain security firm ChainSecurity warned that the proposed changes could affect how deployed smart contracts handle unsuccessful external calls. Some applications use remaining gas balances to determine whether an operation failed permanently or should remain eligible for another attempt.

Under the proposed rules, a failed operation could leave enough gas for the calling contract to continue processing when the same transaction would previously have reverted. ChainSecurity warned that such behavior could cause certain applications to record an unsuccessful operation without allowing users to retry it.

The security firm subsequently discussed its findings on X, with reports describing 13 real-world examples of potentially affected contracts. Researchers have not publicly identified the affected applications, while responsible disclosure efforts remain underway.

⚠️ It has just been decided to delay the Glamsterdam hard fork on the Hoodi testnet because of security impacts we identified in this blog post: https://t.co/UCpy6Jp5Pa

We already found 13 real-world examples and are in responsible disclosure with the affected projects.
Please…

— ChainSecurity (@chain_security) October 22, 2026

Meanwhile, these concerns cover contract mechanisms used in batched transactions, withdrawals and other operations that depend on failure-handling rules. The technical assessment describes how insufficient-gas failures could interfere with existing safeguards without requiring changes to deployed contract code.

Hoodi node operators receive revised client instructions

Following the postponement, the Ethereum Foundation instructed operators to review their execution-layer and consensus-layer software before October 26. Clients retaining the original activation configuration must be updated to prevent them from attempting the previously scheduled fork.

The Foundation’s revised release table lists Lodestar v1.50.1 for the consensus layer, while execution-layer releases include Besu 26.10.1 and Nethermind 2.2.1. Ethrex v30.0.1-rc.2 appears as a prerelease, with instructions for other clients awaiting confirmation.

Validator operators must check both their beacon nodes and validator clients, including any external block-building infrastructure. The Foundation warned that releases listed in the previous Hoodi announcement should not be treated as confirmation that they support the postponement.

Ethereum’s Glamsterdam activation on Sepolia proceeded on October 6, allowing developers to examine the upgrade’s performance with a higher gas limit. The Hoodi postponement concerns a separate testnet and does not reverse the earlier Sepolia activation.

Ethereum mainnet upgrade date remains undecided

Before the postponement, developers had discussed December 1, December 8 and December 9 as possible Glamsterdam mainnet activation dates. The October 22 meeting agenda proposed selecting a date the following week if Hoodi testing proceeded successfully.

None of those dates received final confirmation, and the Foundation’s latest announcement does not establish a replacement schedule. Developers must continue examining the compatibility concerns before announcing another Hoodi activation.

Glamsterdam includes enshrined proposer-builder separation and block-level access lists, changes intended to improve Ethereum’s transaction processing capabilities. 

Previously, Curve Finance highlighted potential DeFi benefits, while warning that revised gas charges could affect some applications.

The Ethereum Foundation confirmed that mainnet users and ETH holders do not need to take action because of the postponement. Application developers have been instructed not to plan further Hoodi testing around the canceled October 26 activation.