Optimism shipped kona v1.5.2 patches ahead of Glamsterdam. The optional host fix is quietly the security story.
The required client patch aligns kona's gas pricing for Glamsterdam. The optional host fix closes a preimage verification gap that exists right now.
CryptoVibe Desk · optimism · fault-proofs · glamsterdam
- →Optimism released kona-client v1.5.2 (required before Glamsterdam) and kona-host v1.5.2 (optional) on May 25.
- →The client patch corrects FPVM gas pricing for EIP-7904, preventing fault-proof programs from running the wrong gas schedule during disputes after Glamsterdam activates.
- →If most Optimism Stack chains skip the optional kona-host patch before Glamsterdam activates, their fault-proof programs will run without preimage hash verification.
- FPVM → The Fault Proof Virtual Machine is a sandboxed environment that re-executes Optimism transactions to settle disputes about what state the chain is actually in.
- preimage oracle → A data feed that supplies raw byte data to the fault-proof program when it needs to verify inputs during a dispute.
- output root → A cryptographic fingerprint of L2 state that Optimism posts to Ethereum L1 to prove what happened on the rollup, used to finalize withdrawals.
- Glamsterdam → Optimism's next major upgrade, which introduces EIP-7904 among other changes and requires kona to update how it prices precompile operations.
Optimism's kona stack just got two patch releases ahead of Glamsterdam. Both are labeled v1.5.2. One is required. One is optional. The optional one carries the more important security fix.
kona is Optimism's fault-proof client. It re-executes L2 state transitions to settle on-chain disputes. It runs inside the FPVM and sources data from preimage oracles. When it runs wrong, fault proofs break.
kona-client v1.5.2 has three changes. It bumps FPVM precompile oracle gas for EIP-7904, which Glamsterdam introduces. It aligns the interop trace-extension boundary with op-program. And it validates output-root version words. Optimism says this version is required before Glamsterdam activates on L1, and optional before that.
The gas bump is the critical change. EIP-7904 changes how precompile costs are calculated. If kona-client's FPVM runs the wrong gas schedule during a dispute, it will reach different conclusions than the canonical chain. That's not a corner case. That's a fault-proof failure mode.
kona-host v1.5.2 is where the security story lives. The release notes describe it as defense-in-depth: the host now verifies that preimage bytes hash to the key that was requested. The old code trusted the oracle's output. The new code checks it.
The label is precise: defense-in-depth means closing inputs that shouldn't reach production but could. In fault-proof infrastructure, that class includes any path where a malformed oracle response goes undetected. And that's the catch with calling this one optional: the host patch applies right now, today, before Glamsterdam is anywhere near L1.
A kona-node v1.5.2 shipped separately on May 19, carrying overlapping client fixes. These releases are coordinated, not coincidental.
If you run kona in any Optimism Stack deployment, the sequence matters. Ship kona-client v1.5.2 before Glamsterdam activates on L1. Ship kona-host v1.5.2 before that if you can. The trace-extension fix is forward-looking. The preimage verification is not.
Optimism calling kona-host v1.5.2 optional undersells the risk. Every Stack chain running kona without it has an unguarded preimage oracle right now. That gap exists today, not after Glamsterdam.
Before Glamsterdam activates on L1, check whether Stack chains outside OP Mainnet have deployed kona-host v1.5.2. If most haven't, the Superchain's fault-proof coverage has a documented gap.
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