Ethereum pulls Monday's Glamsterdam test fork after a security firm finds a gas change that could let contracts keep running after a failed call; 13 real-world contracts potentially affected

Ethereum's next big upgrade has hit a safety snag. The Ethereum Foundation said on Thursday, October 22, 2026, that the Glamsterdam fork on the Hoodi test network, scheduled for Monday, October 26, at 17:42:48 UTC, is postponed and that no new activation date has been set. Core developers decided on their ACDE #248 call (All Core Devs Execution, per CoinDesk) "to allow for further investigation of interactions of EIP-8037 with mainnet smart contracts," the Foundation wrote. The planned increase of Hoodi's gas limit to 200 million was pulled too.

The worry comes from a review that ChainSecurity published on October 13. EIP-8037 changes how Ethereum charges for creating new storage and adds a separate state-gas reservoir; EIP-8038 reprices state access. Together, the auditors found, gas can flow back to a contract after a failed operation, so a failure path that used to run out of gas and revert could now complete, and a fixed gas budget that was enough before may no longer be. CoinDesk reported the firm's calculation that writing a new storage slot could cost 110,020 gas when the separate budget is exhausted, against 22,100 today. ChainSecurity has not publicly shown that any major production protocol is exploitable, CoinDesk reported, but on Friday it said it had identified 13 real-world examples of potentially affected contracts and was coordinating disclosure, per Cointelegraph.

Glamsterdam, which pairs the Amsterdam execution-layer changes with the Gloas consensus-layer changes per the Foundation's post, went live on the Sepolia testnet on October 6, CoinDesk noted. Developers had been considering an early December mainnet date, Cointelegraph reported; that timetable is now open. What to watch: a revised Hoodi schedule, which the Foundation says will be announced separately, and whether developers change EIP-8037.