Ethereum developers have approved a fix for a rule bug in the upcoming Glamsterdam upgrade that could, under certain conditions, have caused ETH deposited for staking to be credited to another operator’s account.
According to CoinDesk, the change, initially rejected on October 19, was reconsidered and added to Ethereum’s consensus specifications on October 26. For the fix to reach the network, client teams need to implement the change in their software.
How Could ETH Deposited for Staking Have Gone to the Wrong Account?
Glamsterdam separates the roles of block builders, which bundle transactions into blocks, and validators, which select and approve those blocks. Both parties can deposit ETH, but those funds need to be tracked in separate accounts.
Researcher avsetsin identified a scenario in which this separation could break down when processing deposits that had not yet been credited during the upgrade. If an operator first registered as a block builder with a particular public key, and then a staking service deposited ETH using the same key to launch a validator, the draft rules could have credited both deposits to the block builder.
According to the researcher, in this case the operator could have withdrawn the funds belonging to the staking service. Since no validator would have been created, the service provider might also have been unable to produce the proof needed to recover its money.
Fix Rejected First, Then Approved
Justin Traglia, who maintains the Ethereum consensus specifications, said on October 19, when closing the proposal, that client teams had not provided enough support for the change. After a second review, the proposal was reopened, avsetsin added tests on October 23, and Traglia merged the fix on October 26.
The new rule separates pending deposits according to the information that determines which account can withdraw the funds. This ensures that even if the block builder uses the same public key, ETH deposited for a validator remains in the validator’s account.
No Live Attack or Losses Reported
Avsetsin also examined possible effects on Lido, Origin, and Rocket Pool, but emphasized that the findings depend on how each protocol handles deposits. Existing checks that reject keys with a prior block builder deposit may prevent the described scenario.
The researcher said these were conditional code findings, not confirmed live attacks; no losses were reported in connection with the story. The fix has now been added to the rules of the upgrade, which is still in development.
Glamsterdam was run on the Sepolia testnet. The trial planned for October 26 on the second testnet, Hoodi, was postponed. A new date for Hoodi needs to be set before the mainnet schedule is determined.
Not investment advice.