taikoxyz taiko-mono up to 2.3.1 TaikoInbox.sol TaikoInbox._verifyBatches array index

Summaryinfo

A vulnerability categorized as critical has been discovered in taikoxyz taiko-mono up to 2.3.1. Affected by this issue is the function TaikoInbox._verifyBatches of the file packages/protocol/contracts/layer1/based/TaikoInbox.sol. Such manipulation leads to array index. This vulnerability is uniquely identified as CVE-2025-66559. The attack can be launched remotely. No exploit exists. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability was found in taikoxyz taiko-mono up to 2.3.1. It has been rated as critical. Affected by this issue is the function TaikoInbox._verifyBatches of the file packages/protocol/contracts/layer1/based/TaikoInbox.sol. The manipulation with an unknown input leads to a array index vulnerability. Using CWE to declare the problem leads to CWE-129. The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2025-66559 since 12/04/2025. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available.

Applying the patch 379f5cb4ffe9e1945563ab2c7740bc9f4ea004d8 is able to eliminate this problem. The bugfix is ready for download at github.com.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• taikoxyz

Name

• taiko-mono

Version

• 2.3.0
• 2.3.1

License

• open-source

Website

• Product: https://github.com/taikoxyz/taiko-mono/

CPE 2.3info

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CPE 2.2info

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