key insights
- Smart contract compatibility drives the delay. ChainSecurity identified 13 potentially affected contract instances involving failure-handling behavior under the proposed gas changes.
- Hoodi operators need updated configurations. Nodes retaining the canceled activation schedule may still attempt the upgrade unless operators install appropriate client updates.
- The date of Ethereum’s mainnet remains to be determined. The postponement was discussed in December, but a new activation schedule has yet to be confirmed by the developers.
The Glamsterdam upgrade to the Hoodi testnet, which was slated for October 26, has been postponed as Ethereum developers continue to look for potential smart contract security issues. The decision delays a key testing milestone for Ethereum’s 2026 upgrade and leaves developers without a confirmed replacement date.
The Ethereum Foundation announced the change on October 22 following discussions during All Core Developers Execution call #248. Developers want to examine how EIP-8037’s revised gas accounting could affect existing smart contracts before scheduling another testnet activation.
Ethereum Postpones Glamsterdam Upgrade on Hoodi Testnet Over EIP-8037 Compatibility Concerns
According to the Ethereum Foundation, Ethereum core developers have postponed the Glamsterdam upgrade on the Hoodi testnet, originally scheduled for October 26, to further investigate… pic.twitter.com/jwbZBiNEDV
— Wu Blockchain (@WuBlockchain) October 23, 2026
Security concerns force a testing reset
The postponement follows a technical assessment from blockchain security firm ChainSecurity, published on October 13. The review examined EIP-8037 and EIP-8038, which change how Ethereum charges for creating and accessing blockchain state.
ChainSecurity warned that the proposed gas changes could weaken protections against insufficient-gas griefing. This pattern of attack is when a caller provides inadequate gas to interfere with a contract’s execution.
The proposed rules would provide for the retention of gas to allow for continuation of a calling contract in some cases where operations failed. Consequently, some contracts might process failure conditions differently from their original design.
That difference could affect applications that depend on transaction failures to preserve retry options or prevent incomplete operations. ChainSecurity identified 13 potentially affected contract instances and began responsible disclosure with the relevant projects.
However, researchers have not publicly identified the affected applications. Ethereum developers have therefore postponed the Hoodi activation while they assess the findings and consider appropriate responses.
Hoodi configuration returns to earlier settings
The canceled activation had been scheduled for October 26 at 17:42:48 UTC, corresponding to Hoodi epoch 132,352. The rollback removes the planned Amsterdam execution-layer and Gloas consensus-layer activations from the testnet configuration.
It also cancels a planned increase in Hoodi’s gas limit to 200 million. Nevertheless, the change affects future upgrade settings rather than the network’s existing transaction history.
Node operators and validators must review their execution-layer and consensus-layer clients. Software that retains the original activation schedule could still attempt the canceled upgrade unless operators install suitable updates.
The revised release information lists Lodestar v1.50.1, while other client instructions require careful verification. Operators should follow the Ethereum Foundation’s updated guidance rather than assume previously listed versions contain the necessary changes.
The distinction matters because client software determines how nodes follow scheduled protocol changes. Therefore, operators must confirm that their installed versions reflect the revised Hoodi configuration before October 26.
Mainnet Plans Face Additional Uncertainty
Glamsterdam already turned on the Ethereum Sepolia testnet on October 6. That deployment is separate, from Hoodi’s delay, which lets developers keep checking the upgrade’s test results.
The bigger upgrade includes protocol proposals. EIP-7732 brings proposer-builder separation. EIP-7928 brings block-level access lists. EIP-8038 tackles gas pricing and state-related costs.
Together these changes try to make transaction processing better and manage the resources needed to keep Ethereum’s growing state running. However, the security review shows why developers need to check how interactions with applications work before rolling out protocol changes more widely.
Before the delay developers talked about Dec 1 , Dec 2 and Dec 9 as dates to activate on the mainnet. Those dates are still not set in stone. The latest news does not give a new schedule for Hoodi.
A new testnet date will be decided after technical work and when clients are ready. Until then application developers should not plan tests around the canceled October 26 activation.
Mainnet Users Are Not Affected
The Ethereum Foundation said that mainnet users and ETH owners do not need to do anything because of the delay. The change is, about the Hoodi upgrade plan and does not cancel Glamsterdam completely.
The main focus now is to find out how the new gas changes affect existing contracts and whether developers need extra protections. Answering these questions will help decide when testing can start again and when a mainnet date is ready.
For Ethereum the delay shows the balance between adding improvements to the protocol and keeping compatibility with the smart contract system. Developers have delayed the Hoodi release to look into risks before choosing another activation date.
