Ethereum Delays Glamsterdam Hoodi Testnet Fork Over Gas Risks

Ethereum developers have postponed the Glamsterdam upgrade on the Hoodi testnet, which had been scheduled for October 26, 2026, and have not set a replacement date, Blockonomi reported. The decision came during All Core Devs Execution call #248, according to the outlet, after security researchers raised concerns about gas changes bundled into the fork.

The Ethereum Foundation said the delay allows developers to examine how certain proposals interact with smart contracts already deployed on Ethereum, Cointelegraph reported.

Key facts

• The postponement removes three items from the October 26 date: the Amsterdam execution layer activation, the Gloas consensus layer activation, and a plan to raise Hoodi’s gas limit to 200 million.
• On October 13, ChainSecurity warned that EIP-8037 and EIP-8038 could weaken protections against insufficient gas griefing attacks.
• ChainSecurity said on Friday it had found 13 real-world examples of smart contracts that could be affected, without naming the projects, and is coordinating responsible disclosure with them (Cointelegraph).
• Glamsterdam already went live on Sepolia on October 6, and that testnet is unaffected by the delay.
• In an October 21 GitHub comment, security researcher pcaversaccio called the risks “serious” and asked developers to reassess the hard fork.

What the gas change actually does

In insufficient gas griefing, a caller supplies too little gas for a valid contract operation to finish. ChainSecurity’s analysis says the new rules could return gas to a contract after a failed operation, letting it keep executing where it would previously have halted. Contracts that depend on remaining gas as a security signal could then misbehave — for instance, erasing a user’s claim or disabling a retry path, leaving a legitimate action impossible to complete.

The firm did not claim every gas-based safeguard breaks. Some checks would still hold, but developers would need to review them against the revised rules. The Ethereum Foundation had earlier cautioned that Glamsterdam’s gas model could disrupt wallets, indexers and gas estimators built on fixed assumptions.

Who has to act

Mainnet users and ETH holders need to do nothing. Node and validator operators, by contrast, must update their software so clients such as Lodestar, Besu and Nethermind run builds confirming the October 26 activation has been withdrawn. The delay does not alter Hoodi’s chain history.

Why it matters

Glamsterdam is Ethereum’s principal scaling upgrade for 2026, bundling enshrined proposer-builder separation under EIP-7732, block-level access lists under EIP-7928, and the contested gas repricing under EIP-8037 and EIP-8038. Because the trouble is confined to a testnet, the effect on market sentiment appears muted: Blockonomi noted ETH showed little reaction, while institutional buying continued, with SharpLink deploying $400 million of its ETH treasury on-chain and BitMine adding 12,535 ETH. The practical consequence is a narrowing window — developers had been eyeing early December for mainnet, contingent on Hoodi passing cleanly.

What to watch

A revised Hoodi date is expected after Devcon, which runs November 3 to 6, according to both reports. The fourth-quarter slot remains open, but the mainnet schedule now hinges on whether the 13 flagged contracts and the wider gas-check review are settled in time.

Nothing here is financial advice, and crypto markets are volatile and unpredictable.

Disclaimer: This article is for information only and is not investment, financial or trading advice. Cryptocurrency prices are highly volatile. Always do your own research.

Sources: Blockonomi, Cointelegraph