ChainSecurity

Trusted by top DeFi engineers since 2017. Born at @ETH_en, ex-@PwC. Probably the most stable team in Web3.

[ChainSecurity @chain_security]

⚠️ It has just been decided to delay the Glamsterdam hard fork on the Hoodi testnet because of security impacts we identified in this blog post: https://t.co/A6rIgIP8zV

We already found 13 real-world examples and are in responsible disclosure with the affected projects.
Please check your contracts as soon as possible, as the EF is determining how many contracts are impacted in which way.

Feel free to reach out to us with questions via [email protected].

[ChainSecurity @chain_security]

Background: https://t.co/C7smDuRnyU

[Ethereum Foundation @ethereumfndn]

The Glamsterdam upgrade on Hoodi testnet previously scheduled for October 26th has been delayed. Node operators check your clients for instructions. The new date is TBA.
https://t.co/xKLIivB5Fm

[The Block @TheBlockCo]

THE BLOCK: Ethereum Foundation announced that it is postponing the Glamsterdam upgrade on the Hoodi testnet, previously set for Oct. 26, for further review of EIP-8037 interactions with mainnet smart contracts.

No new activation date has been announced.

[Lido @LidoFinance]

Lido Glamsterdam on Hoodie Update

On yesterday’s ACDE #248 call, Ethereum core developers made the decision to postpone the Glamsterdam upgrade on the Hoodi testnet to allow for further investigation into how EIP-8037 and EIP-8038 interacts with mainnet contracts:

https://t.co/TTc5Er0ENm

This testnet upgrade delay does not affect the mainnet Lido protocol, and no action is required from stETH or wstETH holders.

Since Lido’s Hoodi contracts had already been upgraded ahead of the previously scheduled October 26 activation, contributors are currently preparing a Hoodi vote to roll back the fork-specific changes and keep the testnet operational until a new upgrade date is set.

Lido DAO contributors are proactively coordinating the rollback with Lido Node Operators and the broader Ethereum ecosystem. If you operate a Hoodi node or validator, please make sure to check both your Execution and Consensus Layer clients for instructions reflecting the postponed activation before October 26.

Lido contributors have been screening EIP-8037 against Lido contracts since June and have found no breaking impact on the protocol’s core contracts so far, which has also been independently confirmed by ChainSecurity.

The review continues alongside the Ethereum core devs’ broader investigation.

[ChainSecurity @chain_security]

@thedaofund @EFDevcon Our team is very excited to discuss this in person too, with everyone attending @EFDevcon

See you soon 🙌

[thedao.fund @thedaofund]

Glamsterdam is bringing changes that could affect how existing smart contracts behave.

@chain_security has already identified 13 affected protocols.

Want to understand what could break and how to check your own code?

Join their workshop at the Security Hub during @EFDevcon on November 5 at 3:40 PM!

RSVP here: https://t.co/gokHHdkK60

[ChainSecurity @chain_security]

In short: after Glamsterdam, some calls that used to fail out of gas can now complete, and contracts built on the old behavior can make the wrong call.

We're working with the EF and affected teams. If you're unsure about your code, reach out via [email protected]

[BeInCrypto @beincrypto]

ETHEREUM JUST PAUSED ITS GLAMSTERDAM TEST.

Ethereum called off the October 26 Glamsterdam test on the Hoodi test network after ChainSecurity warned that two proposed gas-pricing changes could break safeguards in existing contracts.

No new test date has been announced.

[ChainSecurity @chain_security]

🫡

[Decrypt @DecryptMedia]

Ethereum Delays Glamsterdam Testnet Fork Over Gas Security Flaws
https://t.co/d1REUVRB04

[ChainSecurity @chain_security]

🫡

[Laura Shin @laurashin]

Ethereum developers have unscheduled Glamsterdam's Oct. 26 activation on the Hoodi testnet. Christine D. Kim says the reason is security issues ChainSecurity found in the upgrade.

https://t.co/q6N0u7LrF5

[ChainSecurity @chain_security]

We're happy our research could help here. A testnet delay is a lot cheaper than broken contracts on mainnet.
What changes and how to check your code ↓
https://t.co/UFGLVqu1fC

[CoinDesk @CoinDesk]

UPDATE: Ethereum developers postpone the Glamsterdam upgrade on the Hoodi testnet, after security researchers flagged that EIP-8037’s gas accounting changes could permanently alter how existing smart contracts handle failed transactions.

No new date has been announced.

[ChainSecurity @chain_security]

@CoinDesk 🫡🫡🫡

[Unchained @Unchained_pod]

Hoodi node operators: Besu says nodes on v26.10.0 will still activate Amsterdam on Oct. 26 unless they update. Developers had floated Dec. 1, 8 or 9 for Glamsterdam's mainnet launch if Hoodi went smoothly.

https://t.co/1J7oCPCC6R

[defiprime @defiprime]

ChainSecurity found 13 real-world examples affected by Glamsterdam gas changes, prompting a Hoodi fork delay as teams review failure handlers that could disable retries.
https://t.co/MKdTLabQa9

[Crypto Catalyst @CryptoMoneyLife]

ChainSecurity identified 13 real-world examples of smart contracts that could be affected by Ethereum’s Glamsterdam gas changes.

Developers canceled the upgrade’s planned Hoodi testnet activation after a warning that contracts could permanently record failed operations.

ChainSecurity is coordinating responsible disclosure with affected projects. The reports do not say any contracts have been exploited, and no new Hoodi date has been announced.

This is a compatibility issue for applications already deployed—not just a question of whether a new upgrade works on a test network. If you use Ethereum apps, the next milestone is a revised Hoodi plan after developers assess the risk.

[Clay @williamclay]

glamsterdam was supposed to hit the hoodi testnet monday.

core devs pulled it yesterday. no new date.

chainsecurity showed the new gas rules can change how live mainnet contracts handle failures.

testnet delays are cheap.

mainnet surprises aren't.

[BeInCrypto @beincrypto]

ETHEREUM JUST PAUSED ITS GLAMSTERDAM TEST.

Ethereum called off the October 26 Glamsterdam test on the Hoodi test network after ChainSecurity warned that two proposed gas-pricing changes could break safeguards in existing contracts.

No new test date has been announced.

[Defi Security Summit @summit_defi]

Doris Benda · DSS 2026

“How clean is your code? Dirty Bits in Solidity”

Explore the talk and add it to your agenda:
https://t.co/V6lL2V5hfG

Tickets: https://t.co/RTbPxGH7zF

[ChainSecurity @chain_security]

@abcoathup dm'd you

[ChainSecurity @chain_security]

⚠️ It has just been decided to delay the Glamsterdam hard fork on the Hoodi testnet because of security impacts we identified in this blog post: https://t.co/A6rIgIP8zV

We already found 13 real-world examples and are in responsible disclosure with the affected projects.
Please check your contracts as soon as possible, as the EF is determining how many contracts are impacted in which way.

Feel free to reach out to us with questions via [email protected].

[Francesco Andreoli ᵍᵐ @francescoswiss]

Glamsterdam testnet delayed. @chain_security found the new gas rules could change how existing contracts handle failed calls, so devs paused Hoodi to review it first. no new date yet

[ChainSecurity @chain_security]

@klarakova 🤝