Vulnerability · Published Dec 4, 2025 · Assigned by GitHub_M
CVE-2025-66559Taiko Alethia Pacaya inbox verification pointer corruption
High 8.0
In plain English
A high-severity security flaw in taiko-mono from taikoxyz. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| taikoxyz | taiko-mono | <= 2.3.1 |
Weakness: CWE-129 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U