Kona discloses fault-proof soundness fixes and requires operator upgrade

What happened

Optimism published Kona client and host v1.7.0, documenting derivation discrepancies that could let a Byzantine batcher cause Kona and op-node to derive different chains from identical L1 data.

What changed

The available release fixes proof soundness and execution behavior. Operators using kona-client fault proofs are instructed to upgrade, and the changed state transition requires a new absolute prestate.

What did not change

Publication does not establish production installation or on-chain prestate activation. Lagoon interoperability remains outside production according to the release notes.

Confirmed

• Both official releases identify the upgrade as required for chains running kona-client fault proofs.
• The client notes disclose span-batch decoding and decompression discrepancies relative to op-node.
• The proof execution change requires a new absolute prestate.
• The host release also fixes a beacon-blob deserialization crash.

Still open

• Whether the watched Optimism bridge's active production dispute games depend on affected Kona versions.
• Which production operators have installed the release and which absolute prestates are authorized on-chain.
• Whether any disclosed defect was exploited; the release records do not establish exploitation or losses.

What it means for an advisor

• Review the Optimism bridge diligence file's fault-proof implementation and active dispute-game assumptions.
• Obtain production implementation, operator-version, and authorized-prestate evidence before treating this release as completed remediation.