Ethereum core developers have halted the Glamsterdam upgrade fork on the Hoodi testnet after auditor ChainSecurity identified eight smart contract invariants violated by proposed gas pricing changes in EIP-8037 and EIP-8038. The delay is indefinite pending resolution.
Key Takeaways
- Hoodi testnet fork for Glamsterdam delayed indefinitely after ChainSecurity Oct 13 report
- Eight smart contract invariants violated by EIP-8037 and EIP-8038 gas pricing changes
- Risk: contracts assuming fixed gas costs for failed external calls may break
- Glamsterdam already live on Sepolia since Oct 6; mainnet timeline unconfirmed
- Resolution requires EIP modifications or mitigations before Hoodi rescheduling
Executive Intelligence Brief
ChainSecurity Audit Triggers Indefinite Delay
The Ethereum Foundation confirmed Friday that the Hoodi testnet fork will not proceed until security concerns tied to eight smart contract invariants are resolved. The decision followed an Oct. 13 report from ChainSecurity, which found that EIP-8037 and EIP-8038 could break smart contracts relying on fixed gas-related assumptions when external calls fail.
These two Ethereum Improvement Proposals alter how gas is charged for specific operations. Existing projects have built logic assuming certain operations consume a predictable amount of gas; the Glamsterdam changes invalidate those assumptions, creating a class of vulnerability where contracts may behave unexpectedly or fail during execution failures.
Glamsterdam Scope and Sepolia Precedent
Glamsterdam represents a major step in Ethereum's layer-1 scaling roadmap, introducing enshrined proposer-builder separation, block-level access lists, and gas pricing reforms designed to better reflect execution costs. The upgrade went live on the Sepolia testnet on Oct. 6, serving as one of its final major rehearsals before mainnet consideration.
The Hoodi testnet was intended as a subsequent validation environment. Its suspension underscores the Ethereum development culture's preference for rigorous testnet scrutiny over rigid deployment calendars, particularly when backward compatibility with deployed contract logic is at stake.
Technical Mechanics of the Invariant Violations
The eight invariants at risk center on the behavior of external calls that revert or fail. Under current rules, developers can reasonably estimate the gas cost of a failed external call. EIP-8037 and EIP-8038 restructure this pricing, meaning a contract that checks gasleft() after a failing call — or relies on a specific gas stipend — may execute different logic paths, potentially opening reentrancy vectors, breaking access controls, or causing silent logic errors.
ChainSecurity's analysis suggests the impact surface spans any contract making external calls with gas assumptions baked in, a pattern common in DeFi protocols, multisig wallets, and upgradeable proxy patterns.
Forward Outlook and Mainnet Implications
No rescheduled date for the Hoodi fork has been announced. The Ethereum Foundation stated developers need time to identify potential smart contract issues and determine whether changes to the EIPs themselves or mitigations are required. Mainnet deployment remains unconfirmed and contingent on successful testnet validation across all vectors.
Market participants should monitor the Ethereum Foundation blog and core developer calls for the Hoodi rescheduling announcement and any EIP amendments. The Sepolia deployment continues to provide live data on the upgrade's broader functionality.
