Ethereum Fixes Glamsterdam Bug in Staking Deposits
The fix prevents staking deposits from accidentally ending up with builders. It is now included in the consensus rules, but clients still need to implement it.
Key Takeaways
- Ethereum developers patched a Glamsterdam bug that could have assigned staking deposits to builders instead of validators.
- The change was first rejected, but after extra review and testing it was approved on Monday in the consensus specs.
- Client teams still need to work the fix into their software; a new Hoodi date and mainnet timeline are not known yet.
Ethereum developers patched a bug in the upcoming Glamsterdam upgrade that could have caused ETH from staking services to end up with builders instead of new validators. The change was still pushed through on Monday after the same update had been rejected a week earlier.
What Could Have Gone Wrong
Glamsterdam splits two tasks that are still combined today. Builders put together blocks with transactions, while validators stake ETH to secure the network and then choose and confirm those blocks. Both sides can deposit ETH, but that money is supposed to be tracked separately.
The issue was in the way Ethereum would process deposits that were still waiting to be credited. Under the old draft rules, an operator could first register as a builder with a certain public key. If a staking service then deposited ETH to start a validator under that same key, both deposits could be assigned to the builder.
Researcher avsetsin described a scenario in which the operator could withdraw the protocol funds. The validator would then not be created, leaving the staking service without proof to recover the money. According to avsetsin, these were conditional code findings and not confirmed live exploits. No losses have been reported.
Why the Fix Came Back
The proposed change was still closed on October 19. Justin Traglia, who maintains Ethereum's consensus specs, wrote at the time that there was not enough client support to move the change forward. Clients are the separate software programs that run validators to participate in the network.
After more review, the fix was reopened. Avsetsin added tests on October 23, and Traglia approved the change on Monday. Under the new rules, pending deposits are sorted by their withdrawal credentials, the setting that determines where the money can eventually go. That means validator deposits stay with validators, even if a builder uses the same key.
What It Means for Ethereum
The change is now part of Ethereum's consensus specs, but client teams still need to build it into their software. That makes the fix relevant for anyone following the network at the testnet level, especially now that Glamsterdam has already run on Sepolia and the planned launch on Hoodi has been delayed. That delay on Hoodi shows that developers still need to weigh several parts of the upgrade against each other. There is still no new Hoodi date, and without that step, no mainnet date can be set either.
