CVE-2025-66559 Details
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.
A vulnerability in Taiko Alethia's rollup implementation, specifically in the TaikoInbox contract version 2.3.1 and earlier, allows for the corruption of the verification pointer for batch transitions. The issue arises in the _verifyBatches function, where the local transition ID is advanced based on the current block hash before confirming if the batch will be verified. If the verification process is interrupted, the function still updates the verification ID for the last confirmed batch, potentially linking it to an incorrect transition. This flaw can disrupt the integrity of the batch verification chain.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Dec 4, 2025CISA-ADP
Assessed Dec 5, 2025References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/taikoxyz/taiko-mono/commit/379f5cb4ffe9e1945563ab2c7740bc9f4ea004d8 | [email protected] | Source CodeVendor |
| https://github.com/taikoxyz/taiko-mono/security/advisories/GHSA-5mxh-r33p-6h5x | [email protected] | AdvisoryVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-129 | Improper Validation of Array Index | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Taiko Alethia | All versions |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Dec 4, 2025 | New CVE Received | [email protected] |