Ethereum Confirms Oct 6 Glamsterdam Test with Seven-Day Review Window

Ethereum developers confirmed the Oct 6 public test date for the Glamsterdam upgrade. They warned that free test ether enables malicious actors to withhold block payloads. This could disrupt infrastructure testing before mainnet activation.

The attack would not endanger mainnet funds. It targets the Sepolia test network, where test ether has no meaningful cost. A malicious operator could win block auctions and refuse to deliver transactions.

Attackers exploit free test ether

A teenager with disposable builder identities could repeatedly win auctions. They would offer high bids and then withhold the promised transaction payloads. Potuz, an Ethereum consensus developer, stated that any teenager can execute this strategy.

Existing safeguards typically fall back to locally built blocks after several missing payloads. Developers noted that clients must identify and reject individual builders. This prevents attackers from returning under new identities to continue winning bids.

Shortened window for security reviews

Client teams must release Sepolia-ready software by Sept. 29. This leaves seven days before the fork. The standard upgrade process reserves 14 days for security reviews and bug-bounty testing.

Developers accepted the narrower window because Sepolia is relatively centralized. It is easier to recover if something breaks. Production builder software by Titan and Ultrasound has not completed a Glamsterdam transition.

Timeline for mainnet activation

The next public test on Hoodi is tentatively planned for Oct. 27. Developers will decide whether to keep that date after observing Sepolia. A mainnet activation remains unscheduled according to CoinDesk.

Glamsterdam is designed to fit more activity into each block. It supports a block gas limit of about 200 million. This creates room for more payments and trades before users bid higher fees.