Glamsterdam Upgrade Sparks Security Concerns Ahead of Ethereum Mainnet Rollout

Ethereum developers are set to activate the Glamsterdam upgrade on October 6 for the Sepolia testnet. The upgrade, which includes enshrined proposer-builder separation (EIP-7732), aims to separate block construction and validator consensus responsibilities.

The activation will follow a request from client teams to release compatible software by September 29. Developers have expressed concerns that cheap test ether could enable up to 1,000 disposable builders to flood bids and withhold execution payloads.

This has prompted adversarial security tests after the Devnet-11 validated the Gloas transition and raised gas limits from 60 million to 200 million. The testing is crucial as it highlights potential vulnerabilities in the protocol before its planned mainnet rollout in Q4 2026.