Nested Struct in Mapping

Overview

• Severity: High
• Confidence: High
• Affected Versions: 0.4.21 - 0.4.25

What is the Nested Struct in Mapping vulnerability?

For specific older versions of Solidity, mappings containing nested structures would return incorrect values due to a compiler bug. These older versions of Solidity should be avoided for modern smart contract development.

Further reading: GitHub Solidity Repo Issue