Read the docs
TI-2025-40970 Aliases CVE-2025-66559

Taiko Alethia Pacaya inbox verification pointer corruption

Priority MEDIUM 43CWE-129Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Code execution
Confidentiality · integrity · availability
High · High · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-129 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00334 26th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
taikoxyztaiko-monoup to 2.3.1—No fix listedCNA
  • taiko-mono Vendortaikoxyz Affected up to 2.3.1 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-66559

References

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences