Which client caused ETH outage?

TLDR

The Prysm consensus client caused the recent Ethereum (ETH) disruption.

1. A Prysm bug took roughly 23% of validators offline, degrading participation and finality risk (report).
2. The network stayed operational thanks to client diversity among Lighthouse, Teku, Nimbus, and Lodestar (analysis).
3. Operators mitigated it with a temporary flag, --disable-last-epoch-targets, pending fixes (developer guidance).

Deep Dive

1. Scale Of Impact

About 23% of Ethereums validator set went offline due to a Prysm client bug, dropping voting participation close to the threshold where finality can be lost.

1. Coverage noted Prysms share matched the outage magnitude and confirmed the validator participation dip (report).
2. Cointelegraph detailed the bugs effect on outdated state generation and the proximity to the finality threshold (analysis).

2. Why ETH Didnt Fully Halt

Ethereum continued producing blocks because other consensus clients validated normally, illustrating the resilience of client diversity.

1. Lighthouse, Teku, Nimbus, and Lodestar kept the chain moving even as Prysm nodes struggled (analysis).
2. Binances summary attributes the participation decline primarily to Prysm validators, with recovery to near-normal levels afterward (developer guidance).

3. Immediate Mitigation

Operators applied a temporary Prysm workaround flag while developers prepared fixes.

1. The --disable-last-epoch-targets flag was recommended to stabilize affected nodes quickly (analysis).
2. Post-incident data showed voter participation rebounded to near 99%, indicating successful short-term mitigation (developer guidance).

Conclusion

A Prysm client bug caused the validator drop and finality risk, but Ethereum stayed online due to client diversity. The quick workaround and the networks multi-client design limited the disruption, underscoring why spreading stake across multiple clients is central to Ethereums operational resilience.