Delay of the Glamsterdam Update on Ethereum Postpones Activation on Hoodi

Developers have postponed the activation of Glamsterdam on the Hoodi testnet, originally scheduled for October 26, 2026. The delay of the Glamsterdam update on Ethereum follows gas issues reported by ChainSecurity.

The security company explained on Thursday that some smart contracts could permanently record operations intended to remain retriable. The postponement was decided after the company identified the issue in the gas changes of the upgrade.

Key Points

• ChainSecurity found 13 real examples of potentially affected contracts.
• Those managing nodes on Hoodi must use software that removes the scheduled update.
• Glamsterdam is already active on Sepolia, with a gas limit close to 200 million.

The Delay of Glamsterdam on Ethereum Changes Hoodi's Plans

The halt on Hoodi gives developers time to understand how Glamsterdam proposals interact with existing smart contracts. This was explained by the Ethereum Foundation.

ChainSecurity is contacting the involved projects through the responsible disclosure procedure. Meanwhile, the Foundation is assessing how many contracts are exposed.

Ethereum researcher Christine Kim has indicated two paths for node operators. They can revert to a previous version of the software that does not schedule the update, or wait for their execution client team to release a version that removes it.

According to Preston Van Loon, developer of the Prysm consensus client, a release that removes Glamsterdam from the Hoodi schedule would arrive within the day.

When Gas Rules Turn a Retrievable Error into a Permanent Record

The new gas rules of Glamsterdam can undermine the assumptions with which some contracts handle failed external calls. ChainSecurity identified 13 real examples where a failed operation, which the code intended to keep retriable, could instead be recorded permanently.

Gas pays for the computational work on Ethereum. With EIP-8037 and EIP-8038, Glamsterdam changes the costs for creating and querying stored data and adds a separate gas reserve for creating new state.

Some contracts check the available gas, or rely on a call exhausting it, to defend against insufficient gas griefing. In that attack, someone deliberately provides too little gas: a valid operation fails and remains marked as a definitive error.

On October 13, 2026, ChainSecurity warned that the two proposals could weaken these defenses. With Glamsterdam, gas can be replenished or returned after a failed call, while the new cost calculation changes the amount a call requires.

<<Even with unchanged contract code, a failure path that previously ended with a revert can now complete>>, wrote ChainSecurity. The company urged projects to review their contracts.

In practice, the risk does not arise from the contract code, which remains the same, but from the gas rules changing around it.

Sepolia is Already Active, Mainnet Awaits Tests on Hoodi

Glamsterdam is already operational on the Sepolia testnet, where it was activated on October 6, 2026. The blocks use a gas limit of nearly 200 million, more than triple the 60 million of Ethereum's mainnet.

The update also introduces block-level access lists, allowing computers to verify transactions in parallel. It also incorporates into Ethereum's rules the auction that determines who assembles each block.

Before the halt on Hoodi, developers aimed to bring the upgrade to the mainnet by the end of 2026. They had considered early December and would finalize the schedule after successful tests on Hoodi.