Ethereum’s Glamsterdam Test Faces Disruption Risk from Fake Builders

Glamsterdam test — Ethereum developers have scheduled the Glamsterdam upgrade test for October 6 but warn that malicious actors could disrupt the process by exploiting free test ether.

The primary risk involves attackers creating disposable identities, known as “fake builders,” to outbid legitimate participants in Sepolia’s block auctions. If successful, these fake builders could withhold transaction payloads, stalling the test network and hampering infrastructure validation.

While such an attack would not endanger mainnet funds, it could significantly delay testing efforts. The incident highlights a critical need for client software teams to develop methods for identifying and rejecting malicious builders.

Client teams now have a shortened timeline to prepare releases before the Sepolia test. A subsequent test on the Hoodi network is tentatively planned for October 27. A final date for the Glamsterdam activation on the Ethereum mainnet has not been set.