Prysm releases post-incident report on Ethereum Fusaka mainnet network outage on 12/4

Client consensus Ethereum Prysm has published a detailed post-mortem report about the Fusaka mainnet network outage that occurred on 12/4. According to the report, the primary cause was resource exhaustion resulting from re-computing state with high costs when processing certain types of attestations. This abnormal computational pressure triggered a ripple effect, causing the network to miss 41 consecutive epochs.

As a result, network participation temporarily dropped to around 75%, significantly affecting validator performance. Prysm estimates the total validator reward loss during this incident to be approximately 382 ETH.

To address this initially, the Prysm team implemented a temporary measure via a runtime configuration flag to reduce system load. Subsequently, long-term fixes were deployed in versions v7.0.1 and v7.1.0, focusing on improving attestation validation logic and increasing the stability of Ethereum's consensus layer.