Ethereum has recently struggled to process data-heavy blocks after a December upgrade expanded layer 2 data capacity, researchers say. The issue surfaced in recent weeks on the network as layer 2 chains increased blob submissions, raising concern about potential stability risks.
The upgrade, called Fusaka, raised per-block blob capacity roughly eightfold from the prior limit of nine blobs. Developers applied two quick follow-up increases, first to 15 and then to 21 blobs per block, and discussed the change on a December livestream.
Research from MigaLabs found that blocks carrying many blobs are far likelier to be dropped, and warned the problem could threaten network stability if it worsens (Ed. note: this signal warns developers to act). According to the MigaLabs research, the few blob-heavy blocks that test network limits tend to cause following blocks to fail. “My intention was not to be alarmist, but to raise a signal to the core developers and researchers that’s saying, ‘We need to take a look at this,'” the MigaLabs founder said.
A PandaOps review within the Ethereum Foundation reached a similar conclusion but flagged validator timing games and MEV as likely contributors. The PandaOps analysis noted some failures stem from delayed block publishing. “I’m not worried about the network at the moment,” one analyst said, adding caution before further blob increases.
Developers are considering a minor update to improve blob propagation before raising capacity further. Layer 2 projects such as Arbitrum and Base sent most blobs, and teams urge a measured rollout while more analysis finishes.

