CVE-2025-66559 — Taiko Alethia Pacaya inbox verification pointer corruption
Taiko Alethia is an Ethereum-equivalent, permissionless, based rollup designed to scale Ethereum without compromising its fundamental properties. In 2.3.1 and earlier, TaikoInbo…
Published: 2025-12-04 · CVSS: 8.0 · CVSS 4.0
Taiko Alethia is an Ethereum-equivalent, permissionless, based rollup designed to scale Ethereum without compromising its fundamental properties. In 2.3.1 and earlier, TaikoInbox._verifyBatches (packages/protocol/contracts/layer1/based/TaikoInbox.sol:627-678) advanced the local tid to whatever transition matched the current blockHash before knowing whether that batch would actually be verified. When the loop later broke (e.g., cooldown window not yet passed or transition invalidated), the function still wrote that newer tid into batches[lastVerifiedBatchId].verifiedTransitionId after decrementing batchId. Result: the last verified batch could end up pointing at a transition index from the next batch (often zeroed), corrupting the verified chain pointer.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7