What to Know

  • Ethereum developers postponed the Glamsterdam upgrade on the Hoodi test network after security researchers flagged risks tied to proposed gas accounting changes.
  • The Hoodi activation had been scheduled for Oct. 26 at 17:42:48 UTC before developers called it off during Thursday's All Core Devs Execution meeting.
  • Security firm ChainSecurity found that EIP 8037 and EIP 8038 could change how some existing smart contracts behave when called contracts run out of gas.
  • The concern is that certain failed operations could be permanently recorded, while some otherwise valid operations could fail under the new rules.
  • ChainSecurity calculated that creating a new storage slot could require 110,020 gas in one scenario, compared with 22,100 under the old rules.
  • No replacement date has been announced for the Hoodi test, and Ethereum's mainnet upgrade date remains unconfirmed.
  • The planned Hoodi gas limit increase to 200 million has also been postponed.
  • Glamsterdam completed its Sepolia testnet activation on Oct. 6 before the Hoodi delay.

Ethereum Slows Glamsterdam Rollout After Security Review

Ethereum developers have postponed the Glamsterdam upgrade on the Hoodi test network after security researchers identified a risk that could affect how already deployed smart contracts respond to failed transactions. The decision adds a fresh checkpoint to Ethereum's upgrade process, underscoring how protocol changes can have complicated consequences for applications that were written under earlier assumptions about gas behavior.

The Hoodi activation was scheduled for Oct. 26 at 17:42:48 UTC, but developers called off the test during Thursday's All Core Devs Execution meeting. The move gives core contributors more time to examine how the proposed changes interact with contracts already running on Ethereum's main network. No replacement date has been announced for the Hoodi activation, and Ethereum's mainnet upgrade date remains unconfirmed.

At the center of the delay are EIP 8037 and EIP 8038, two proposals tied to Ethereum's evolving gas framework. The most prominent concern relates to EIP 8037, which changes how Ethereum charges for creating new records in its database. The goal is to help manage database growth as the network prepares to process more transactions and support larger blocks, but the mechanics may alter the assumptions that some contracts rely on when handling failed calls.

Why Gas Accounting Matters for Existing Contracts

Gas is the unit Ethereum uses to price computational work and storage activity. Every transaction consumes gas, and smart contracts often make decisions based on how much gas remains after an operation. When one contract calls another contract, the called contract may succeed, fail, or run out of gas. The calling contract can then attempt to catch that failure and continue processing, depending on how it was designed.

That behavior is not merely theoretical. Some contracts are built to record that an attempt failed, disable further attempts, move to another stage, or continue with a fallback path. In many cases, developers have relied on the expectation that if a called contract runs out of gas, the remaining gas will be too low for additional actions to complete. Under that expectation, the entire transaction may reverse rather than permanently storing a failed state or completing a failure handling step.

Glamsterdam's proposed rules could change that calculation. Under the new approach, gas used to create certain records can be restored when those changes are undone. That can leave a contract with enough gas to complete a failure handling operation that would previously have reversed. For contracts that were designed with older gas assumptions in mind, that difference could change the final outcome of a transaction.

The risk also runs in the opposite direction. ChainSecurity calculated that creating a new storage slot could require 110,020 gas when a separate allowance is exhausted, compared with 22,100 under the old rules. That means a contract operating with an existing gas budget could fail while attempting an otherwise valid operation. In practical terms, a transaction that developers expected to succeed could instead halt because the cost profile has changed.

Security Findings Focus on Mechanisms, Not a Confirmed Exploit

The findings focus on how existing software could behave under proposed protocol rules. ChainSecurity has demonstrated the mechanisms behind the concern, but it has not publicly established that a major production protocol is exploitable. That distinction matters for market participants and builders. The issue is significant because it touches deployed contract behavior, but it is not the same as a confirmed live exploit against a major application.

Even so, Ethereum developers tend to treat backward compatibility risks seriously. Ethereum's smart contract ecosystem includes a broad range of protocols, wallets, infrastructure systems, governance tools, trading venues, and financial applications. Many of those systems were built over years of protocol behavior. A subtle change in gas accounting can therefore matter if contracts embedded earlier expectations into their logic.

The postponement shows the value of public test networks in Ethereum's development process. Test networks such as Sepolia and Hoodi provide a proving ground before changes are adopted on mainnet. Glamsterdam completed its Sepolia testnet activation on Oct. 6, and Hoodi was the next public rehearsal. By delaying Hoodi, developers are signaling that the interaction between the proposed gas rules and existing contracts requires more review before the upgrade advances further.

Hoodi Gas Limit Increase Also Put on Hold

The Hoodi test was also expected to include a planned increase in its gas limit to 200 million. That change has now been postponed alongside the Glamsterdam activation. A higher gas limit on a test network allows developers to study how the network behaves under larger block capacity, which is relevant as Ethereum continues working toward better throughput and scalability.

Glamsterdam includes several broader changes beyond the gas accounting issue. Among them is a new system for choosing block builders and improvements intended to let the network handle larger blocks. These features are part of Ethereum's ongoing effort to refine execution layer performance while preserving the reliability of the network. The delay does not cancel those goals, but it does place additional scrutiny on the upgrade path.

For Ethereum users, the immediate impact is limited because the delay affects a test network activation, not mainnet. Transactions and applications on Ethereum's main network continue to operate under the existing rules. However, for developers, auditors, node operators, and infrastructure teams, the pause is meaningful because it may affect testing schedules, integration plans, and assumptions about when Glamsterdam features could reach production.

What Developers Are Likely Watching Next

The next phase will likely involve deeper review of the interaction between EIP 8037, EIP 8038, and existing contract patterns. Technical traders and market participants often watch Ethereum upgrades for potential effects on sentiment, but protocol engineers are focused on whether the proposed behavior can be adjusted, documented, or safely deployed without creating unexpected outcomes for deployed contracts.

One possible area of attention is whether the gas restoration mechanics can be modified to reduce compatibility risk. Another is whether known contract patterns can be tested against the proposed rules to understand how widespread the issue may be. Because Ethereum supports immutable contracts, developers cannot assume that all affected code can be easily upgraded or patched by the teams that originally deployed it.

The absence of a replacement date suggests developers are not rushing the process. That caution fits Ethereum's history of staged upgrades, where testnet rehearsals are used to detect edge cases before mainnet activation. The fact that the mainnet date remains unconfirmed gives contributors more room to evaluate the issue without immediately placing users or major applications under a new gas regime.

For now, Glamsterdam remains an important Ethereum upgrade in progress, but the Hoodi postponement has shifted attention to contract compatibility and gas accounting safety. The core question is whether the proposed changes can achieve their intended database management and scalability benefits without disrupting software that depends on older gas cost assumptions.

Frequently Asked Questions (FAQs)

What happened to Ethereum's Glamsterdam upgrade on Hoodi?

Ethereum developers postponed the Glamsterdam upgrade on the Hoodi test network after security researchers identified risks involving proposed gas accounting changes and existing smart contracts.

When was the Hoodi activation supposed to happen?

The Hoodi activation was scheduled for Oct. 26 at 17:42:48 UTC before developers called it off during Thursday's All Core Devs Execution meeting.

Has Ethereum announced a new Hoodi activation date?

No replacement date has been announced for the Hoodi test, and Ethereum's mainnet upgrade date also remains unconfirmed.

Which Ethereum proposals are involved in the concern?

The concern centers on EIP 8037 and EIP 8038, which could alter how some contracts behave when gas is consumed, restored, or exhausted during contract interactions.

What did ChainSecurity find?

ChainSecurity found that the proposed gas changes could leave some contracts with more or less gas than expected, potentially allowing failed operations to be recorded or causing valid operations to fail.

Does this mean a major Ethereum protocol has been exploited?

No. ChainSecurity has demonstrated the mechanisms behind the risk, but it has not publicly established that a major production protocol is exploitable.

Why does gas accounting matter for smart contracts?

Smart contracts often rely on gas availability to determine whether operations complete, fail, reverse, or trigger fallback behavior, so changes in gas rules can affect transaction outcomes.

What happened to the planned 200 million gas limit on Hoodi?

The planned increase of Hoodi's gas limit to 200 million has also been postponed alongside the Glamsterdam activation.

Did Glamsterdam already activate on another test network?

Yes. Glamsterdam completed its Sepolia testnet activation on Oct. 6 before the Hoodi activation was delayed.