# Ethereum Network Threat Involving RPC Size Limits Between the Merge and Dencun

DevFeed: [Ethereum Network Threat Involving RPC Size Limits Between the Merge and Dencun](<https://devfeed.tech/articles/sepolia-incident-17097.md>)

Original publisher: [Read original article](<https://blog.ethereum.org/en/2024/03/21/sepolia-incident>)

Author: Marius van der Wijden; Toni Wahrstätter; Parithosh Jayanthi

Published: 2024-03-21T00:00:00Z

Content type: article

Language: en

Sources: [Ethereum Foundation Blog](<https://devfeed.tech/sources/ethereum-foundation-blog.md>)

Topics: [incident](<https://devfeed.tech/topics/incident.md>), [Ethereum](<https://devfeed.tech/topics/ethereum.md>), [Network](<https://devfeed.tech/topics/network.md>), [Remote Procedure Call (RPC)](<https://devfeed.tech/topics/rpc.md>), [HTTP](<https://devfeed.tech/topics/http.md>)

Tags: [attacks](<https://devfeed.tech/tags/attacks.md>), [chaos](<https://devfeed.tech/tags/chaos.md>), [ethereum](<https://devfeed.tech/tags/ethereum.md>), [http](<https://devfeed.tech/tags/http.md>), [incident](<https://devfeed.tech/tags/incident.md>), [issue](<https://devfeed.tech/tags/issue.md>), [network](<https://devfeed.tech/tags/network.md>), [rpc](<https://devfeed.tech/tags/rpc.md>), [security](<https://devfeed.tech/tags/security.md>)

## AI overview

The article discloses an Ethereum network threat caused by differing RPC message-size limits carried into the engine API. This could allow blocks that some clients accepted while others rejected, potentially causing blocks to be forked away. The article also reports that lowering limits to 5MB did not fully resolve the issue because blocks could reach that limit through many sub-128KB transactions.

## Source excerpt

This blog post discloses a threat against the Ethereum network that was present from the Merge up until the Dencun hard fork....