Ethereum developers have canceled the planned activation of the Glamsterdam upgrade on the Hoodi testnet, just four days before its scheduled implementation. The move leaves the network’s next hard fork without a finalized public testing date, delaying the timeline for selecting a mainnet launch.
Security findings halt rollout
Christine D. Kim, founder of the crypto research and advisory firm Protocol Watch, stated on October 22 that the cancellation followed security issues uncovered by the cybersecurity company ChainSecurity. Kim posted on X that ChainSecurity had identified problems in the Glamsterdam upgrade significant enough to halt the testnet deployment.
An analysis by ChainSecurity, released on October 13, examined EIP-8037 and EIP-8038—two proposals within Glamsterdam that modify Ethereum’s gas charging model for creating and accessing state. According to the firm, the upgrade could cause smart contracts to behave differently in failure scenarios, even when their code remains unchanged. The analysis cautioned that a “failure path that previously reverted can now complete,” which could convert retryable operations into permanent failures.
Mini dictionary: ChainSecurity, a cybersecurity company specializing in blockchain and smart contract audits, is known for identifying vulnerabilities in major blockchain upgrades to help prevent potential exploits and security breaches.
ChainSecurity warned that even with no changes to contract code, failure conditions that once led to reverts could now allow operations to proceed, creating new classes of permanent failures.
Developer response and suspension process
Before the Ethereum All Core Devs Execution call on October 22, security researcher pcaversaccio urged developers on GitHub to review ChainSecurity’s findings, emphasizing the need to reassess the hard fork. However, he noted the decision would rest with Ethereum’s core development team.
Shortly afterward, Kim advised node operators to either revert to an older release without the Hoodi upgrade or await further updates that would remove the upgrade altogether.
On October 22, Besu developers, who maintain one of Ethereum’s main client implementations, merged a pull request titled “Unschedule Amsterdam on Hoodi.” The update does not automatically change nodes that are already running the previous version; nodes operating on Besu 26.10.0 will still activate the upgrade until they have the new release installed.
Barnabas Busa, part of the Ethereum Foundation’s DevOps team, also removed the upgrade schedule from Hoodi’s shared network configuration files. This rollback eliminated the programmed launch date of October 26 for Amsterdam, the upcoming Gloas fork at epoch 132,352, and an increase in Hoodi’s gas limit to 200 million at that same epoch, restoring the original configuration.
Technical teams returned Hoodi’s network settings to their earlier state, removing all planned hard fork events and leaving the upgrade timeline uncertain.
Delay impacts hard fork timeline
Originally, the schedule for Hoodi’s testnet upgrade was announced by the Ethereum Foundation on October 16. The agenda for the October 22 all-core developers call had included potential mainnet deployment dates for the Glamsterdam upgrade—December 1, December 8, and December 9—with the intention to finalize a date after successful Hoodi testing.
The Glamsterdam upgrade introduces key features to the Ethereum protocol, including EIP-7732, which embeds proposer-builder separation at the protocol level, and EIP-7928, which adds block-level access lists. The upgrade had previously been tested on Sepolia, one of Ethereum’s testnets, since October 6.
At present, neither Kim nor Busa have announced a new date for the Hoodi testnet upgrade. The next steps and the mainnet timeline will likely be determined only after further analysis and security verification by the development community.
